Pharmacological inhibition of STAT3 pathway ameliorates acute liver injury in vivo via inactivation of inflammatory macrophages and hepatic stellate cells

Over Activation of IL-6/STAT3 Signaling Pathway in Juvenile Dermatomyositis

INTRODUCTION

Juvenile dermatomyositis (JDM) is characterized by persistent non-purulent inflammation in the muscle and skin. The underlying mechanisms still remain uncertain. This study aims to elucidate the mechanism of interleukin-6 (IL-6) activation of Janus kinase/signal transducer and activator of transcription 3 pathway (JAK/STAT3), contributing to the pathogenesis of JDM.

METHODS

Serum IL-6 levels were compared between 72 newly diagnosed patients with JDM and the same patient cohort in treatment remission. Single-cell RNA sequencing (scRNA-seq) was employed to identify differential signaling pathway expression in muscle biopsy samples from two patients with JDM and healthy controls. Immunohistochemistry was used to examine differences in STAT3 phosphorylation between JDM and control muscle tissues. In vitro, skeletal muscle cell lines were stimulated with IL-6, and the transcription levels of genes related to mitochondrial calcium channels were quantified via reverse transcription-polymerase chain reaction (RT-PCR). Reactive oxygen species (ROS) production was measured in both IL-6 treated and untreated groups. ROS levels were then compared between IL-6 receptor antagonist pre-treated skeletal muscle cells and untreated cells.

RESULTS

IL-6 levels in newly onset patients with JDM were significantly higher compared to the same patient cohort in remission states (p < 0.0001). Serum IL-6 was significantly increased in patients with negative myositis specific antibody (MSA), positive melanoma differentiation associated protein 5 (MDA5) and positive nuclear matrix protein 2 (NXP2), yet not for JDM with positive transcriptional intermediary factor γ (TIF1γ), based on subgroup analysis. ScRNA-seq analysis of muscle biopsies from patients with MDA5-positive JDM and patients with MSA negative JDM revealed abnormal activation of the JAK/STAT3 pathway in skeletal myocytes, macrophages, and vascular endothelial cells. The phosphorylation levels of STAT3 were elevated in active JDM cases. Transcription of the calcium channel modulation gene sarcolipin (SLN) was significantly higher in JDM primary skeletal muscle cells compared to normal cells. In vitro, IL-6 enhanced SLN transcription and induced ROS production, and blocking the IL-6 receptor resulted in decreased ROS generation in skeletal muscle cells.

CONCLUSIONS

IL-6/JAK/STAT3 signaling pathway was abnormally activated in patients with JDM. IL-6 may be involved in the pathogenesis of muscle damage by triggering the development of calcium overload and production of ROS. Blockade of the IL-6/JAK/STAT3 pathway can be a potential treatment option for JDM, especially MDA5-positive patients and those who are negative for MSA.

Subcutaneous administration of Stattic alleviates neuropathic pain by relieving inflammation in a mouse model of postherpetic neuralgia

Stattic, a commercial inhibitor of STAT3, can drive the development of neuropathic pain. Exploring the connection between Stattic and JAK1/STAT3 signaling may facilitate the understanding of neuropathic pain caused by postherpetic neuralgia (PHN). In the current study, as crucial regulators of inflammation, STAT3 and its associated JAK1/STAT3 pathway were found to be upregulated and activated in the L4-L6 dorsal root ganglion (DRG) of mice in response to resiniferatoxin (RTX)-induced PHN, while subcutaneous administration of Stattic was found to downregulate STAT3 expression and phosphorylation in a PHN model. Stattic administration further attenuated hypersensitivity to mechanical and thermal stimuli in PHN mice, and alleviated inflammation and cell death in the L4-L6 DRG of mice. Overexpression of STAT3 via microinjection of a lentiviral-STAT3 overexpression vector reversed the abnormal decrease of STAT3 at both the mRNA and protein levels in the L4-6 DRGs of PHN mice and significantly promoted hypersensitivity to mechanical stimuli in the mice. Collectively, we found that subcutaneous static administration alleviated RTX-induced neuropathic pain by deactivating JAK1/STAT3 in mice.

Hydroxytyrosol attenuates ethanol-induced liver injury by ameliorating steatosis, oxidative stress and hepatic inflammation by interfering STAT3/iNOS pathway

Objective: Hydroxytyrosol (HT) is a polyphenol with a wide range of biological activities. Excessive drinking can lead to oxidative stress and inflammation in the liver, which usually develop into alcohol liver disease (ALD). At present, there is no specific drug to treat ALD. In this paper, the protection effect of HT on ALD and the underline mechanism were studied.Methods: HepG2 cells were exposed to ethanol in vitro and C57BL/6J mice were fed with a Lieber-DeCarli ethanol liquid diet in vivo.Results: triglyceride (TG) level in serum and the expression of fatty acid synthase (FASN) were reduced significantly by the treatment with HT The acetaldehyde dehydrogenase (ALDH) activity was increased, the serum level of malondialdehyde (MDA) was decreased, catalase (CAT) and glutathione (GSH) were increased, suggesting that HT may reduce its oxidative damage to the body by promoting alcohol metabolism. Furthermore, according to the mRNA levels of tnf-α, il-6 and il-1β, HT inhibited ethanol-induced inflammation significantly. The anti-inflammatory mechanism of HT may be related to suppress the STAT3/iNOS pathway.Dissussion: Our study showed that HT could ameliorate ethanol-induced hepatic steatosis, oxidative stress and inflammation and provide a new candidate for the prevention and treatment of ALD.

Stattic ameliorates the cecal ligation and puncture-induced cardiac injury in septic mice via IL-6-gp130-STAT3 signaling pathway

AIM

Sepsis-induced cardiac dysfunction is the leading cause of higher morbidity and mortality with poor prognosis in septic patients. Our recent previous investigation provides evidence of the hallmarks of signal transducer and activator of transcription3 (STAT3) activation in sepsis and targeting of STAT3 with Stattic, a small-molecule inhibitor of STAT3, has beneficial effects in various septic tissues. We investigated the possible cardioprotective effects of Stattic on cardiac inflammation and dysfunction in mice with cecal ligation and puncture (CLP)-induced sepsis.

MAIN METHODS

A polymicrobial sepsis model was induced by CLP in mice and Stattic (25 mg/kg) was intraperitoneally given at one and twelve hours after CLP operation. The cecum was exposed in sham-control mice without CLP. After 18 h of surgery, electrocardiogram (ECG) for anaesthized mice was registered followed by collecting of samples of blood and tissues for bimolecular and histopathological assessments. Myeloperoxidase, a marker of neutrophil infiltration, was assessed immunohistochemically.

KEY FINDINGS

CLP profoundly impaired cardiac functions as evidenced by ECG changes in septic mice as well as elevation of cardiac enzymes, and inflammatory markers with myocardial histopathological and immunohistochemical alterations. While, Stattic markedly reversed the CLP-induced cardiac abnormalities and restored the cardiac function by its anti-inflammatory activities.

SIGNIFICANCE

Stattic treatment had potential beneficial effects against sepsis-induced cardiac inflammation, dysfunction and damage. Its cardioprotective effects were possibly attributed to its anti-inflammatory activities by targeting STAT3 and downregulation of IL-6 and gp130. Our investigations suggest that Stattic could be a promising target for management of cardiac sepsis and inflammation-related cardiac damage.

Therapeutic inhibition of miR-155 attenuates liver fibrosis via STAT3 signaling

Most chronic liver diseases progress to liver fibrosis, which, when left untreated, can lead to cirrhosis and hepatocellular carcinoma. MicroRNA (miRNA)-targeted therapeutics have become attractive approaches to treat diseases. In this study, we investigated the therapeutic effect of miR-155 inhibition in the bile duct ligation (BDL) mouse model of liver fibrosis and evaluated the role of miR-155 in chronic liver fibrosis using miR-155-deficient (miR-155 knockout [KO]) mice. We found increased hepatic miR-155 expression in patients with cirrhosis and in the BDL- and CCl4-induced mouse models of liver fibrosis. Liver fibrosis was significantly reduced in miR-155 KO mice after CCl4 administration or BDL. To assess the therapeutic potential of miR-155 inhibition, we administered an rAAV8-anti-miR-155 tough decoy in vivo that significantly reduced liver damage and fibrosis in BDL. BDL-induced protein levels of transforming growth factor β (TGF-β), p-SMAD2/3, and p-STAT3 were attenuated in anti-miR-155-treated compared with control mice. Hepatic stellate cells from miR-155 KO mice showed attenuation in activation and mesenchymal marker expression. In vitro, miR-155 gain- and loss-of-function studies revealed that miR-155 regulates activation of stellate cells partly via STAT3 signaling. Our study suggests that miR-155 is the key regulator of liver fibrosis and might be a potential therapeutic target to attenuate fibrosis progression.

Molecular characterization and function of JAK/STAT pathway in IPEC-J2 cells during Clostridium perfringens beta2 toxin stimulation

Intestinal infection with C. perfringens is responsible for outbreaks of diarrhea in piglets. Janus kinase / signal transducer and activator of transcription (JAK/STAT) is a vital signaling pathway that regulates cellular activity and inflammatory response, closely correlated with multiple diseases development and advances. Currently, the potential effect of JAK/STAT on C. perfringens beta2 (CPB2) treatment on porcine intestinal epithelial (IPEC-J2) cells has not been explored. The expression of JAK/STAT genes or proteins in IPEC-J2 cells induced by CPB2 were observed by qRT-PCR and Western blot, and further used WP1066 to explore the effect of JAK2/STAT3 on mechanism employed by CPB2 on apoptosis, cytotoxicity, oxidative stress and inflammatory cytokines of IPEC-J2 cells. JAK2, JAK3, STAT1, STAT3, STAT5A and STAT6 were highly expressed in CPB2-induced IPEC-J2 cells, among which STAT3 had the highest expression. Moreover, apoptosis, cytotoxicity and oxidative stress were attenuated via blocking the activation of JAK2/STAT3 by using WP1066 in CPB2-treated IPEC-J2 cells. Furthermore, WP1066 significantly suppressed the secretion of interleukin (IL)-6, IL-1β and TNF-α induced by CPB2 in IPEC-J2 cells.Our findings provide some insights into the functional roles of JAK2/STAT3 in piglets against to C. perfringens infection.

Spinal muscular atrophy-like phenotype in a mouse model of acid ceramidase deficiency

Mutations in ASAH1 have been linked to two allegedly distinct disorders: Farber disease (FD) and spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME). We have previously reported FD-like phenotypes in mice harboring a single amino acid substitution in acid ceramidase (ACDase), P361R, known to be pathogenic in humans (P361R-Farber). Here we describe a mouse model with an SMA-PME-like phenotype (P361R-SMA). P361R-SMA mice live 2-3-times longer than P361R-Farber mice and have different phenotypes including progressive ataxia and bladder dysfunction, which suggests neurological dysfunction. We found profound demyelination, loss of axons, and altered sphingolipid levels in P361R-SMA spinal cords; severe pathology was restricted to the white matter. Our model can serve as a tool to study the pathological effects of ACDase deficiency on the central nervous system and to evaluate potential therapies for SMA-PME.

Small-molecule natural plants for reversing liver fibrosis based on modulation of hepatic stellate cells activation: An update

BACKGROUND

Liver fibrosis (LF) is a trauma repair process carried out by the liver in response to various acute and chronic liver injuries. Its primary pathological characteristics are excessive proliferation and improper dismissal of the extracellular matrix, and if left untreated, it will progress into cirrhosis, liver cancer, and other diseases. Hepatic stellate cells (HSCs) activation is intimately associated to the onset of LF, and it is anticipated that addressing HSCs proliferation can reverse LF. Plant-based small-molecule medications have anti-LF properties, and their mechanisms of action involve suppression of extracellular matrix abnormally accumulating as well as anti-inflammation and anti-oxidative stress. New targeting HSC agents will therefore be needed to provide a potential curative response.

PURPOSE

The most recent HSC routes and small molecule natural plants that target HSC described domestically and internationally in recent years were examined in this review.

METHODS

The data was looked up using resources including ScienceDirect, CNKI, Web of Science, and PubMed. Keyword searches for information on hepatic stellate cells included "liver fibrosis", "natural plant", "hepatic stellate cells", "adverse reaction", "toxicity", etc. RESULTS: We discovered that plant monomers can target and control various pathways to prevent the activation and proliferation of HSC and promote the apoptosis of HSC in order to achieve the anti-LF effect in this work by compiling the plant monomers that influence many common pathways of HSC in recent years. It demonstrates the wide-ranging potential of plant monomers targeting different routes to combat LF, with a view to supplying new concepts and new strategies for natural plant therapy of LF as well as research and development of novel pharmaceuticals. The investigation of kaempferol, physalin B, and other plant monomers additionally motivated researchers to focus on the structure-activity link between the main chemicals and LF.

CONCLUSION

The creation of novel pharmaceuticals can benefit greatly from the use of natural components. They are often harmless for people, non-target creatures, and the environment because they are found in nature, and they can be employed as the starting chemicals for the creation of novel medications. Natural plants are valuable resources for creating new medications with fresh action targets because they feature original and distinctive action mechanisms.

A therapeutic role of exosomal lncRNA H19 from adipose mesenchymal stem cells in cutaneous wound healing by triggering macrophage M2 polarization

BACKGROUND

Emerging evidence has figured out that adipose mesenchymal stem cells (ADSCs) promote wound healing. Exosomes, which act as main paracrine factors and contains various protein, lncRNA, and miRNAs, play a critical role in wound healing. Nevertheless, the mechanism remains to be elucidated. This study aims to identify the underlying mechanism of ADSCs-derived exosome (ADSCs-exos)-mediated wound healing.

METHODS

ADSCs-exos were characterized using the transmission electron microscope, dynamic light scattering, and western blot. ELISA, RT-qPCR, flow cytometry, western blot, CCK-8 assay, transwell assay and tube formation were employed to validate the actions of ADSCs-exos harboring H19 in cell polarization, proliferation, migration and angiogenesis. The regulatory axis among H19, miR-130b-3p and PPARγ or STAT3 was confirmed by RNA pull-down, RIP assay and dual-luciferase reporter assays.

RESULTS

ADSCs-exos harboring H19 promoted macrophage M2 polarization, thereby enhancing fibroblast proliferation, migration and endothelial cell angiogenesis. However, their promotive effects were disrupted within H19 depletion in ADSCs-exos. Additionally, miR-130b-3p, directly targeting PPARγ or STAT3, was identified to be a downstream effector to participate in H19-mediated biological effects. Moreover, ADSCs-exos carrying H19 modulated cutaneous wound healing via H19/miR-130b-3p -mediated macrophage M2 polarization in vivo.

CONCLUSION

Collectively, ADSCs-derived exosomal H19 accelerates cutaneous wound healing via the miR-130b-3p/PPARγ/STAT3 axis, indicating potential therapeutic strategies for the treatment of wound healing.

Collagen matrix scaffolds: Future perspectives for the management of chronic liver diseases

Approximately 1.5 billion chronic liver disease (CLD) cases have been estimated worldwide, encompassing a wide range of liver damage severities. Moreover, liver disease causes approximately 1.75 million deaths per year. CLD is typically characterized by the silent and progressive deterioration of liver parenchyma due to an incessant inflammatory process, cell death, over deposition of extracellular matrix proteins, and dysregulated regeneration. Overall, these processes impair the correct function of this vital organ. Cirrhosis and liver cancer are the main complications of CLD, which accounts for 3.5% of all deaths worldwide. Liver transplantation is the optimal therapeutic option for advanced liver damage. The liver is one of the most common organs transplanted; however, only 10% of liver transplants are successful. In this context, regenerative medicine has made significant progress in the design of biomaterials, such as collagen matrix scaffolds, to address the limitations of organ transplantation (e.g., low donation rates and biocompatibility). Thus, it remains crucial to continue with experimental and clinical studies to validate the use of collagen matrix scaffolds in liver disease.

Role of NADPH Oxidase-Derived ROS-Mediated IL-6/STAT3 and MAPK/NF-κB Signaling Pathways in Protective Effect of Corilagin against Acetaminophen-Induced Liver Injury in Mice

Acetaminophen (APAP) overdose causes acute liver injury via oxidative stress, uncontrolled inflammatory response, and subsequent hepatocyte death. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a potent source of cellular reactive oxygen species (ROS) and may contribute to oxidative stress in many inflammatory processes. Corilagin, a component of Phyllanthus urinaria, possesses antioxidant, anti-inflammatory, and hepatoprotective effects. We evaluated the mechanisms underlying the protective effect of corilagin against acetaminophen-induced liver injury. Mice were intraperitoneally administrated 300 mg/kg APAP or equal volume of saline (control), with or without various concentrations of corilagin (0, 1, 5, or 10 mg/kg) administered after 30 min. All animals were sacrificed 16 h after APAP administration, and serum and liver tissue assays including histology, immunohistochemistry, and Western blot assay were performed. Corilagin post-treatment significantly attenuated APAP-induced liver injury (p < 0.005), inflammatory cell infiltration, hepatic proinflammatory cytokine levels, and hepatic oxidative stress. Furthermore, corilagin attenuated the protein levels of NOX1, NOX2, signal transducer and activator of transcription 3 (STAT3), and nuclear factor kappa B (NF-κB) in APAP-induced liver injury. These results indicated that the antioxidant, anti-inflammatory, and protective effects of corilagin in APAP-induced liver injury might involve the regulation of interleukin (IL)-6/STAT3 and mitogen-activated protein kinase (MAPK)/NF-κB signaling pathways through NOX-derived ROS.

The research development of STAT3 in hepatic ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) is a common complication of surgery, which can cause rapid deterioration of the liver function, increase the risk of graft rejection, and seriously affect the prognosis of patients. The signal transducer and activator of transcription 3 (STAT3) protein has been implicated in pathogenesis of IRI. STAT3 influences the mitochondria through multiple pathways and is also involved in apoptosis and other forms of programmed cell death. STAT3 is associated with Janus kinase (JAK), phosphoinositide-3 kinase (PI3K), and heme oxygenase-1 (HO-1) in liver IRI. The STAT3 pathway plays a dual role in IRI as it can also regulate lipid metabolism which may have potential for treating IRI fatty liver. In this review, we summarize research on the function of STAT3 in liver IRI to provide references for its application in the clinic.

Overexpression of estrogen receptor β inhibits cellular functions of human hepatic stellate cells and promotes the anti-fibrosis effect of calycosin via inhibiting STAT3 phosphorylation

BACKGROUND

Estrogen receptor β (ERβ) is the major ER subtype in hepatic stellate cells (HSCs). Previously we reported phytoestrogen calycosin suppressed liver fibrosis progression and inhibited HSC-T6 cell functions, suggesting the effects may be related to ERβ. Here, we explore the effect of overexpressed ERβ on human HSCs and the role of ERβ in pharmacological action of calycosin.

METHODS

LX-2 cells were transfected with lentivirus to overexpress ERβ. In the presence or absence of overexpressed ERβ, the effects of ERβ and calycosin on proliferation, migration, activation, collagen production and degradation of TGF-β1-induced LX-2 cells and the role of ERβ in the inhibition effect of calycosin were investigated. LX-2 cells overexpressed with ERβ or treated with ER non-selective antagonist ICI182,780 were used to investigate the regulation of ERβ on JAK2/STAT3 signaling pathway. CCK-8 method was used to screen effective doses of calycosin and investigate cell proliferation. The cell migration was detected by transwell chamber assay. The expression of α-SMA was detected by immunofluorescence and western blot. The protein expressions of Col-I, MMP1, TIMP1, JAK2, p-JAK2, STAT3 and p-STAT3 were detected by western blot.

RESULTS

ERβ overexpressed lentivirus was successfully transfected into LX-2 cells with high efficiency. Overexpressed ERβ or calycosin alone inhibited the TGF-β1-induced LX-2 cell proliferation and migration, downregulated the protein expressions of α-SMA, Col-I, TIMP-1, p-STAT3 and upregulated MMP-1. Both overexpressed ERβ and calycosin had no significant effect on JAK2, p-JAK2 and STAT3 expressions. ERβ overexpression further enhanced the above effects of calycosin. However, after the cells were treated with ICI182,780, downregulation of STAT3 phosphorylation induced by calycosin was reversed.

CONCLUSIONS

ERβ mediated the inhibition of major functions of LX-2 cell possibly by inhibiting the phosphorylation of STAT3, and was an important pathway through which calycosin exerted anti-liver fibrosis effect.

A Unique Immune-Related Gene Signature Represents Advanced Liver Fibrosis and Reveals Potential Therapeutic Targets

Innate and adaptive immune responses are critically associated with the progression of fibrosis in chronic liver diseases. In this study, we aim to identify a unique immune-related gene signature representing advanced liver fibrosis and to reveal potential therapeutic targets. Seventy-seven snap-frozen liver tissues with various chronic liver diseases at different fibrosis stages (1: n = 12, 2: n = 12, 3: n = 25, 4: n = 28) were subjected to expression analyses. Gene expression analysis was performed using the nCounter PanCancer Immune Profiling Panel (NanoString Technologies, Seattle, WA, USA). Biological meta-analysis was performed using the CBS Probe PINGSTM (CbsBioscience, Daejeon, Korea). Using non-tumor tissues from surgically resected specimens, we identified the immune-related, five-gene signature (CHIT1_FCER1G_OSM_VEGFA_ZAP70) that reliably differentiated patients with low- (F1 and F2) and high-grade fibrosis (F3 and F4; accuracy = 94.8%, specificity = 91.7%, sensitivity = 96.23%). The signature was independent of all pathological and clinical features and was independently associated with high-grade fibrosis using multivariate analysis. Among these genes, the expression of inflammation-associated FCER1G, OSM, VEGFA, and ZAP70 was lower in high-grade fibrosis than in low-grade fibrosis, whereas CHIT1 expression, which is associated with fibrogenic activity of macrophages, was higher in high-grade fibrosis. Meta-analysis revealed that STAT3, a potential druggable target, highly interacts with the five-gene signature. Overall, we identified an immune gene signature that reliably predicts advanced fibrosis in chronic liver disease. This signature revealed potential immune therapeutic targets to ameliorate liver fibrosis.

TLR9 Signaling Protects Alcohol-Induced Hepatic Oxidative Stress but Worsens Liver Inflammation in Mice

Toll-Like Receptor 9 (TLR9) elicits cellular response to nucleic acids derived from pathogens or dead cells. Previous studies have shown that TLR9-driven response may lead to differential impact on the pathogenesis of liver diseases. This study aimed to determine how TLR9 may contribute to chronic alcohol exposure-induced liver pathogenesis. We observed that TLR9 KO mice were more susceptible to alcohol-induced liver injury, which was evidenced by higher serum ALT/AST levels and more lipid accumulation in alcohol-fed TLR9 KO mice than wild-type mice. Alcohol-induced oxidative stress and mitochondrial dysfunction were also exacerbated by TLR9 KO. We found that chronic alcohol exposure-induced hepatic CHOP and ATF6 activation were enhanced in TLR9 KO mice. By using primary hepatocytes and AML-12 cells, we confirmed that TLR9 activation by CpG ODN administration significantly ameliorated acetaldehyde-induced cell injury via suppressing ATF6-CHOP signaling. By using STAT3 knockdown AML12 cells, we showed that TLR9-mediated STAT3 activation inhibited ATF6-CHOP signaling cascade and thereby protecting against acetaldehyde-induced mitochondrial dysfunction and cell injury. Interestingly, we found that TLR9 KO mice ameliorate chronic alcohol exposure-induced CXCL1 induction and neutrophils infiltration in the liver. Furthermore, hepatocyte lack of STAT3 significantly ameliorated CpG ODN and LPS-increased CXCL1 levels in hepatocytes. Overall, our data demonstrate that TLR9 signaling in hepatocytes counteracts alcohol-induced hepatotoxicity but worsens proinflammatory response.

Targeting S100A4 with niclosamide attenuates inflammatory and profibrotic pathways in models of amyotrophic lateral sclerosis

Background

An increasing number of studies evidences that amyotrophic lateral sclerosis (ALS) is characterized by extensive alterations in different cell types and in different regions besides the CNS. We previously reported the upregulation in ALS models of a gene called fibroblast-specific protein-1 or S100A4, recognized as a pro-inflammatory and profibrotic factor. Since inflammation and fibrosis are often mutual-sustaining events that contribute to establish a hostile environment for organ functions, the comprehension of the elements responsible for these interconnected pathways is crucial to disclose novel aspects involved in ALS pathology.

Methods

Here, we employed fibroblasts derived from ALS patients harboring the C9orf72 hexanucleotide repeat expansion and ALS patients with no mutations in known ALS-associated genes and we downregulated S100A4 using siRNA or the S100A4 transcriptional inhibitor niclosamide. Mice overexpressing human FUS were adopted to assess the effects of niclosamide in vivo on ALS pathology.

Results

We demonstrated that S100A4 underlies impaired autophagy and a profibrotic phenotype, which characterize ALS fibroblasts. Indeed, its inhibition reduces inflammatory, autophagic, and profibrotic pathways in ALS fibroblasts, and interferes with different markers known as pathogenic in the disease, such as mTOR, SQSTM1/p62, STAT3, α-SMA, and NF-κB. Importantly, niclosamide in vivo treatment of ALS-FUS mice reduces the expression of S100A4, α-SMA, and PDGFRβ in the spinal cord, as well as gliosis in central and peripheral nervous tissues, together with axonal impairment and displays beneficial effects on muscle atrophy, by promoting muscle regeneration and reducing fibrosis.

Conclusion

Our findings show that S100A4 has a role in ALS-related mechanisms, and that drugs such as niclosamide which are able to target inflammatory and fibrotic pathways could represent promising pharmacological tools for ALS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02184-1.

Current Understanding of the Immunomodulatory Activities of High-Density Lipoproteins

Lipoproteins interact with immune cells, macrophages and endothelial cells - key players of the innate and adaptive immune system. High-density lipoprotein (HDL) particles seem to have evolved as part of the innate immune system since certain HDL subspecies contain combinations of apolipoproteins with immune regulatory functions. HDL is enriched in anti-inflammatory lipids, such as sphingosine-1-phosphate and certain saturated lysophospholipids. HDL reduces inflammation and protects against infection by modulating immune cell function, vasodilation and endothelial barrier function. HDL suppresses immune cell activation at least in part by modulating the cholesterol content in cholesterol/sphingolipid-rich membrane domains (lipid rafts), which play a critical role in the compartmentalization of signaling pathways. Acute infections, inflammation or autoimmune diseases lower HDL cholesterol levels and significantly alter HDL metabolism, composition and function. Such alterations could have a major impact on disease progression and may affect the risk for infections and cardiovascular disease. This review article aims to provide a comprehensive overview of the immune cell modulatory activities of HDL. We focus on newly discovered activities of HDL-associated apolipoproteins, enzymes, lipids, and HDL mimetic peptides.

Participation of ABCA1 Transporter in Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is the important medical and social problem. According to modern concepts, COPD is a chronic inflammatory disease, macrophages play a key role in its pathogenesis. Macrophages are heterogeneous in their functions, which is largely determined by their immunometabolic profile, as well as the features of lipid homeostasis, in which the ATP binding cassette transporter A1 (ABCA1) plays an essential role. The objective of this work is the analysis of the ABCA1 protein participation and the function of reverse cholesterol transport in the pathogenesis of COPD. The expression of the ABCA1 gene in lung tissues takes the second place after the liver, which indicates the important role of the carrier in lung function. The participation of the transporter in the development of COPD consists in provision of lipid metabolism, regulation of inflammation, phagocytosis, and apoptosis. Violation of the processes in which ABCA1 is involved may be a part of the pathophysiological mechanisms, leading to the formation of a heterogeneous clinical course of the disease.

Endoplasmic reticulum stress and autophagy are involved in adipocyte-induced fibrosis in hepatic stellate cells

Liver fibrosis, with the characterization of progressive accumulation of extracellular matrix (ECM), is the common pathologic feature in the process of chronic liver disease. Hepatic stellate cells (HSCs) which are activated and differentiate into proliferative and contractile myofibroblasts are recognized as the main drivers of fibrosis. Obesity-related adipocytokine dysregulation is known to accelerate liver fibrosis progression, but the direct fibrogenic effect of mature adipocytes on HSCs has been rarely reported. Therefore, the purpose of this study was to explore the fibrogenic effect of adipocyte 3T3-L1 cells on hepatic stellate LX-2 cells. The results showed that incubating LX-2 cells with the supernatant of 3T3-L1 adipocytes triggered the expression of ECM related proteins, such as α-smooth muscle actin (α-SMA), type I collagen (CO-I), and activated TGF β/Smad2/3 signaling pathway in LX-2 cells. In addition, 3T3-L1 cells inhibited insulin sensitivity, activated endoplasmic reticulum stress and autophagy to promote the development of fibrosis. These results supported the notion that mature adipocytes can directly activate hepatic stellate cells, and the establishment of an in vitro model of adipocytes on HSCs provides an insight into screening of drugs for liver diseases, such as nonalcoholic fatty liver disease.

Stattic alleviates acute hepatic damage induced by LPS/d-galactosamine in mice

Increasing evidence indicates that signal transducer and activator of transcription 3 (STAT3), a vital transcription factor, plays crucial roles in the regulation of inflammation. STAT3 has become a novel therapeutic target for intervention in inflammation-related disorders. However, it remains unclear whether STAT3 plays a part in acute hepatic damage. To investigate the effects of STAT3 here, LPS/d-GalN-induced hepatic damage was induced in mice, the STAT3 inhibitor Stattic was administered, and the degree of liver injury, inflammation, and hepatocyte apoptosis were investigated. The results showed that Stattic mitigated the hepatic morphologic abnormalities and decreased the level of aminotransferase in LPS/D-GalN-insulted mice. The results also indicated that Stattic decreased the levels of TNF-α and IL-6, prevented the activation of the caspase cascade, suppressed cleavage of PARP, and decreased the quantity of TUNEL-positive cells. These results suggest that Stattic provided protective benefits in LPS/d-GalN-induced hepatic damage, and the protective effects might be associated with its anti-inflammatory and anti-apoptotic effects. Therefore, STAT3 might become a novel target for intervening in inflammation-based and apoptosis-based hepatic disorders.

A novel role of nifuroxazide in attenuation of sepsis-associated acute lung and myocardial injuries; role of TLR4/NLPR3/IL-1β signaling interruption

Acute lung injury (ALI) and the subsequent multi-system organ failure is a serious health problem with devastating impacts on the health care systems. Indeed, the world has been facing an un-preceded situation in the past couple of months following COVID-19 infestation and the associated high-mortality rates mainly attributed to sepsis and the associated multiple organ failures of particular concern; acute respiratory distress syndrome post lung injury. The current study provides evidence on the ameliorative impact of nifuroxazide, and FDA approved antidiarrheal drug in attenuation of lipopolysaccharide (LPS)-induced ALI and myocarditis when administrated either in prophylactic or curative regimens. Nifuroxazide administration was associated with a significant improvement in lung and heart histopathological characteristics and architecture with retraction of LPS-induced inflammatory-infiltration. This was associated with retraction in serum biomarkers of cellular injury of which; LDH, CK-MB, and ALP. Nifuroxazide administration was associated with a significant improvement in both lung and heart oxidative status. Such positive outcomes were underlined by a significant inhibitory effect of nifuroxazide on lung and heart contents of toll-like receptor (4) (TLR4)/the inflammasome NALPR3/interleukin- 1β (IL-1β). In conclusion: Nifuroxazide attenuates LPS-induced ALI and myocardial injury via interruption of TLR4/NALPR3/IL-1β signaling. Thus it can offer a potential approach for attenuation of sepsis in critically ill patients.