Macrophage p38α promotes nutritional steatohepatitis through M1 polarization

Overexpression of SERPINA3 inhibits castration-resistant prostate cancer progression by enhancing M1 macrophage recruitment via CXCL2 upregulation

The primary objective of the present study was to identify differentially expressed genes (DEGs) associated with castration-resistant prostate cancer (CRPC) to verify the potential mechanism of CRPC progression. DEGs from CRPC datasets were filtered with a P<0.05 and Spearman correlation coefficient ≥0.3. Serpin peptidase inhibitor, clade A member 3 (SERPINA3), was uniquely present in three CRPC datasets, and its low expression in CRPC was confirmed in cell lines and tissues. Colony formation, transwell assays, and subcutaneous tumor formation experiments in mice demonstrated that overexpression of SERPINA3 may significantly inhibit the proliferation and invasion of PC3 cells. Mechanistic studies revealed that, in prostate cancer (PCa), SERPINA3 can activate the interleukin (IL)-17 and tumor necrosis factor (TNF)α signaling pathways by promoting the expression of CXC chemokine ligand 2 (CXCL2), thereby increasing the recruitment of M1 macrophages into the tumor microenvironment and inhibiting the progression of PCa. The current results indicated that the expression of SERPINA3 may be negatively correlated with CRPC, and it could promote the M1 polarization of macrophages and inhibit the progression of CRPC by increasing the expression of CXCL2.

Endogenous sulfur dioxide deficiency impairs bone regeneration through abolishing S-sulfenylating p38 at cysteine 211

Bone defects result in substantial medical expenses and a diminished quality of life for patients. Macrophage polarization is crucial in the bone regeneration process mediated by bone marrow-derived mesenchymal stem cells (BMSCs). macrophage-derived sulfur dioxide (SO2), the fourth endogenous gas signaling molecule, following hydrogen sulfide (H2S), has been shown to regulate macrophage chemotaxis and inflammatory responses. Nevertheless, the specific regulatory effects and mechanisms of macrophage-derived SO2 on bone regeneration are not yet fully understood. This study reveals for the first time that the absence of macrophage-derived SO2 promotes M1 macrophage polarization, whereas the administration of exogenous SO2 donors inhibits M1 polarization. The deficiency of macrophage-derived SO2 results in impaired osteogenic differentiation of BMSCs, whereas the administration of SO2 donors enhances this differentiation process. Further investigations have elucidated that p38α MAPK (p38) is crucial in mediating SO2's effects on M1 macrophage polarization and BMSCs osteogenic differentiation. Mechanistically, SO2 induces S-sulfenylation of p38 in macrophages, an effect that can be reversed by the thiol reductant dithiothreitol. Additionally, the C211S mutation in p38 abrogates the SO2-induced S-sulfenylation of p38, thereby preventing the inhibition of p38 activation and subsequently disrupting the regulation of M1 macrophage polarization and BMSCs osteogenic differentiation. In a model of mouse calvarial bone defects, we consistently observed that inhibiting SO2 production using the SO2-generating enzyme inhibitor HDX impaired bone regeneration capacity in mice, whereas the administration of an SO2 donor enhanced this capacity. In summary, macrophage-derived SO2 S-sulfenylates p38 at cysteine 211, thereby suppressing p38 activation, which inhibits M1 polarization and subsequently maintains the osteogenic differentiation of BMSCs. This study is the first to elucidate the role and mechanism of SO2 in sustaining osteogenesis, offering a novel strategy for addressing bone defect-related disorders.

Aging and metabolic dysfunction-associated steatotic liver disease: a bidirectional relationship

In recent years, aging and cellular senescence have triggered an increased interest in corresponding research fields. Evidence shows that the complex aging process is involved in the development of many chronic liver diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). In fact, aging has a tremendous effect on the liver, leading to a gradual decline in the metabolism, detoxification and immune functions of the liver, which in turn increases the risk of liver disease. These changes can be based on the aging of liver cells (hepatocytes, liver sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells). Similarly, patients with liver diseases exhibit increases in the aging phenotype and aging cells, often manifesting as faster physical functional decline, which is closely related to the promoting effect of liver disease on aging. This review summarizes the interplay between MASLD/MASH development and aging, aiming to reveal the complex relationships that exacerbate one another. Moreover, the corresponding schemes for delaying aging or treating diseases are discussed to provide a basis for the development of effective prevention and treatment strategies in the future.

Macrophage polarization in cancer and beyond: from inflammatory signaling pathways to potential therapeutic strategies

Macrophages are innate immune cells distributed throughout the body that play vital roles in organ development, tissue homeostasis, and immune surveillance. Macrophages acquire a binary M1/M2 polarized phenotype through signaling cascades upon sensing different signaling molecules in the environment, thereby playing a core role in a series of immune tasks, rendering precise regulation essential. M1/M2 macrophage phenotypes regulate inflammatory responses, while controlled activation of inflammatory signaling pathways is involved in regulating macrophage polarization. Among the relevant signaling pathways, we focus on the six well-characterized NF-κB, MAPK, JAK-STAT, PI3K/AKT, inflammasome, and cGAS-STING inflammatory pathways, and elucidate their roles and crosstalk in macrophage polarization. Furthermore, the effects of many environmental signals that influence macrophage polarization are investigated by modulating these pathways in vivo and in vitro. We thus detail the physiological and pathophysiological status of these six inflammatory signaling pathways and involvement in regulating macrophage polarization in cancer and beyond, as well as describe potential therapeutic approaches targeting these signaling pathways. In this review, the latest research advances in inflammatory signaling pathways regulating macrophage polarization are reviewed, as targeting these inflammatory signaling pathways provides suitable strategies to intervene in macrophage polarization and various tumor and non-tumor diseases.

M6A Modified miR-31-5p Suppresses M1 Macrophage Polarization and Autoimmune Dry Eye by Targeting P2RX7

The dysregulation of the M1/M2 macrophage balance plays a pivotal role in autoimmune diseases. However, the interplay between microRNAs (miRNAs) and N6-methyladenosine (m6A) modulation in regulating this balance remains poorly understood. Here, a significant reduction in miR-31-5p levels is observed in the lacrimal glands of rabbit autoimmune dacryoadenitis and the peripheral blood mononuclear cells (PBMCs) of Sjögren's syndrome (SS) dry eye patients. Overexpression of miR-31-5p exhibits preventive and therapeutic effects on rabbit autoimmune dacryoadenitis. Further investigation revealed that miR-31-5p overexpression significantly restored the M1/M2 macrophage balance both in vivo and in vitro. Mechanistically, miR-31-5p directly targets the P2x7 receptor (P2RX7), leading to the inactivation of p38 mitogen-activated protein kinases (MAPK) signaling and reduced expression of M1 markers. Furthermore, methylated RNA immunoprecipitation and luciferase reporter assays demonstrated that fat mass and obesity-associated protein (FTO)-mediated m6A demethylation, which sustains pri-miR-31 stability, is responsible for the decreased miR-31-5p levels in autoimmune dry eye. Notably, PBMC samples from SS dry eye patients further support the link between reduced miR-31-5p levels and M1 macrophage activation observed in rabbits. Overall, these data highlight the critical role of the FTO/miR-31-5p/P2RX7/p38 MAPK axis in autoimmune inflammation, suggesting their potential as therapeutic targets for autoimmune dry eye.

Zwitterionic Brush-Grafted Interfacial Bio-Lubricant Evades Complement C3-Mediated Macrophage Phagocytosis for Osteoarthritis Therapy

Administering a bio-lubricant is a promising therapeutic approach for the treatment of osteoarthritis (OA), in particular, if it can both manage symptoms and halt disease progression. However, the clearance of these bio-lubricants mediated by synovial macrophages leads to reduced therapeutic efficiency and adverse inflammatory responses. Herein, it is shown that this process is predominantly mediated by the specific binding of complement C3 (on nanoparticle) and CD11b (on macrophage). More importantly, through a systematic evaluation of various interface modifications, a macrophage-evading nanoparticle strategy is proposed, which not only minimizes friction, but also largely suppresses C3 adsorption. It involves employing a zwitterionic poly-2-methacryloyloxyethyl phosphorylcholine (PMPC) brush layer grafted from a crosslinked gelatin core. In vitro studies demonstrate that such a nanoparticle lubricant can evade macrophage phagocytosis and further prevent the pro-inflammatory M1 polarization and subsequent harmful release of cytokines. In vivo studies show that the designed PMPC brush layer effectively mitigates synovial inflammation, alleviates OA-associated pain, and protects cartilage from degeneration, thus preventing OA progression. These findings clarify the pivotal role of complement C3-mediated macrophage recognition in nanoparticles clearance and offer a promising nanoparticle design strategy to restore joint lubrication.

High glucose-induced alternative splicing of MEF2D in macrophages promotes vascular chronic inflammation in type 2 diabetes mellitus by mediating M1 macrophage polarization

OBJECTIVES

To investigate the effects of a high-glucose environment in type 2 diabetes mellitus (T2DM) on Myocyte enhancer factor 2d (MEF2D) selective splicing and its impact on the disease process and mechanism.

METHODS

Human monocyte (THP-1) cells were induced into macrophages with phorbol 12-myristate 13-acetate (PMA), and treated with high glucose for 24 h. PCR confirmed MEF2D splicing products. MEF2D or MEF2D-AS overexpression vectors were transfected into macrophages, and ELISA detected inflammatory factors; flow cytometry analyzed MI/M2 phenotypes; and levels of LC3, PI3K, and LAMP2 were measured. Autophagic flux detection; co-immunoprecipitation detected MEF2D and KCNMA1 interaction; WB and RT-qPCR assessed KCNMA1 expression. Macrophages co-cultured with endothelial cells were analyzed by ELISA for vascular inflammation factors MMP-9, Cys-C, and hsCRP.

RESULTS

High glucose-induced alternative splicing of MEF2D at 86-132 aa. MEF2D-AS group showed higher inflammatory factors, increased M1 phenotype, lower autophagy gene expression, and higher vascular inflammation factors compared to MEF2D group. Autophagy activator Rapamycin or KCNMA1 overexpression reversed these effects. MEF2D targeted KCNMA1, and MEF2D-AS overexpression led to decreased KCNMA1, increased inflammatory factors, M1 polarization, autophagy inhibition, and higher vascular inflammation factors.

CONCLUSION

High glucose induces MEF2D alternative splicing in macrophages, inhibiting autophagy and promoting M1 polarization via KCNMA1 down-regulation, thus promoting chronic inflammation in T2DM vessels.

Hepatocellular carcinoma: pathogenesis, molecular mechanisms, and treatment advances

Hepatocellular Carcinoma (HCC), a highly prevalent malignancy, poses a significant global health challenge. Its pathogenesis is intricate and multifactorial, involving a complex interplay of environmental and genetic factors. Viral hepatitis, excessive alcohol consumption, and cirrhosis are known to significantly elevate the risk of developing HCC. The underlying biological processes driving HCC are equally complex, encompassing aberrant activation of molecular signaling pathways, dysregulation of hepatocellular differentiation and angiogenesis, and immune dysfunction. This review delves into the multifaceted nature of HCC, exploring its etiology and the intricate molecular signaling pathways involved in its development. We examine the role of immune dysregulation in HCC progression and discuss the potential of emerging therapeutic strategies, including immune-targeted therapy and tumor-associated macrophage interventions. Additionally, we explore the potential of traditional Chinese medicine (TCM) monomers in inhibiting tumor growth. By elucidating the complex interplay of factors contributing to HCC, this review aims to provide a comprehensive understanding of the disease and highlight promising avenues for future research and therapeutic development.

Defining gastric cancer ecology: the crucial roles of TREM2+ macrophages and fibroblasts in tumor microenvironments

Gastric cancer (GC) remains a major global health challenge, characterized by a complex tumor microenvironment (TME) that significantly influences disease progression and therapeutic outcomes. This study focuses on TREM2+ lipid-associated macrophages (LAM) and cancer-associated fibroblasts (CAFs) in modulating the GC microenvironment. Utilizing advanced single-cell RNA sequencing and bulk RNA analyses, we elucidated the interactive mechanisms through which CAFs enhance the immunosuppressive capabilities of TREM2+ LAMs via the CXCL12-CXCR4 signaling axis. Our findings reveal that this interaction facilitates tumor proliferation and inhibits apoptotic processes in GC cells. In vitro experiments confirmed the modulation of this pathway significantly affects tumor cell viability and invasiveness, underscoring the critical roles of these cellular interactions in promoting GC progression. These insights present TREM2+ LAMs and CAFs as potential therapeutic targets, offering new avenues for improving outcomes in GC treatment.

Hexokinase 2-mediated metabolic stress and inflammation burden of liver macrophages via histone lactylation in MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by metabolic dysfunction and inflammation burden, involving a significant enhancement of cellular glycolytic activity. Here, we elucidate how a positive feedback loop in liver macrophages drives MASLD pathogenesis and demonstrate that disrupting this cycle mitigates metabolic stress and macrophage M1 activation during MASLD. We detect elevated expression of hexokinase 2 (HK2) and H3K18la in liver macrophages from patients with MASLD and MASLD mice. This lactate-dependent histone lactylation promotes glycolysis and liver macrophage M1 polarization by enriching the promoters of glycolytic genes and activating transcription. Ultimately, the HK2/glycolysis/H3K18la positive feedback loop exacerbates the vicious cycle of enhancing metabolic dysregulation and histone lactylation and the inflammatory phenotype of liver macrophages. Myeloid-specific deletion of Hk2 or pharmacological inhibition of the transcription factor HIF-1α significantly disrupts this deleterious cycle. Therefore, our study illustrates that targeting this amplified pathogenic loop may offer a promising therapeutic strategy for MASLD.

Secreted chemokines and transcriptomic analyses reveal diverse inflammatory and degenerative processes in the intervertebral disc of the STZ-HFD mouse model of Type 2 diabetes

The chronic inflammation resultant from type 2 diabetes (T2D) is also associated with spinal pathologies, including intervertebral disc (IVD) degeneration and chronic neck and back pain. Although confounding factors, such as increased weight gain in obesity, studies have shown that even after adjusting age, body mass index, and genetics (e.g. twins), patients with T2D suffer from disproportionately more IVD degeneration and back pain. We hypothesize that chronic T2D fosters a proinflammatory microenvironment within the IVD that promotes degeneration and disrupts disc homeostasis. To test this hypothesis, we evaluated two commonly used mouse models of T2D - the leptin-receptor deficient mouse (db/db) and the chronic high-fat diet in mice with impaired beta-cell function (STZ-HFD). STZ-HFD IVDs were more degenerated and showed differential expression of chemokines from the db/db models. Moreover, the RNAseq analysis revealed vast transcriptional dysregulation of many pathways in the STZ-HFD but not in the db/db tissues. Leptin signaling may be essential to mediating the inflammation in T2D. Taken together, the STZ-HFD may better recapitulates the complexities of the chronic inflammatory processes in the IVD during T2D.

FGF21 ameliorates septic liver injury by restraining proinflammatory macrophages activation through the autophagy/HIF-1α axis

INTRODUCTION

Sepsis, a systemic immune syndrome caused by severe trauma or infection, poses a substantial threat to the health of patients worldwide. The progression of sepsis is heavily influenced by septic liver injury, which is triggered by infection and cytokine storms, and has a significant impact on the tolerance and prognosis of septic patients. The objective of our study is to elucidate the biological role and molecular mechanism of fibroblast growth factor 21 (FGF21) in the process of sepsis.

OBJECTIVES

This study was undertaken in an attempt to elucidate the function and molecular mechanism of FGF21 in therapy of sepsis.

METHODS

Serum concentrations of FGF21 were measured in sepsis patients and septic mice. Liver injury was compared between mice FGF21 knockout (KO) mice and wildtype (WT) mice. To assess the therapeutic potential, recombinant human FGF21 was administered to septic mice. Furthermore, the molecular mechanism of FGF21 was investigated in mice with myeloid-cell specific HIF-1α overexpression mice (LyzM-CreDIO-HIF-1α) and myeloid-cell specific Atg7 knockout mice (Atg7△mye).

RESULTS

Serum level of FGF21 was significantly increased in sepsis patients and septic mice. Through the use of recombinant human FGF21 (rhFGF21) and FGF21 KO mice, we found that FGF21 mitigated septic liver injury by inhibiting the initiation and propagation of inflammation. Treatment with rhFGF21 effectively suppressed the activation of proinflammatory macrophages by promoting macroautophagy/autophagy degradation of hypoxia-inducible factor-1α (HIF-1α). Importantly, the therapeutic effect of rhFGF21 against septic liver injury was nullified in LyzM-CreDIO-HIF-1α mice and Atg7△mye mice.

CONCLUSIONS

Our findings demonstrate that FGF21 considerably suppresses inflammation upon septic liver injury through the autophagy/ HIF-1α axis.

Exosome-equipped TNF antisense oligodeoxynucleotide or 2-deoxy-D-glucose ameliorated nonalcoholic steatohepatitis by modulating superoxide dismutase 1 in mice

Inflammatory mediators tumor necrosis factor (TNF) and interleukin 1 beta (IL1β), primarily derived from hepatic macrophages in the liver, play a crucial role in the progression of nonalcoholic steatohepatitis (NASH). Meanwhile, intravenously injected exosomes are mainly distributed in the liver and predominantly taken up by hepatic macrophage. Herein, we aimed to evaluate the feasibility of targeted inhibition of TNF and IL1β expression in hepatic macrophages via exosomes as a potential therapeutic strategy for NASH. In this study, we demonstrated that antisense oligodeoxynucleotide targeting TNF (ASO-TNF) or 2-deoxy-d-glucose (2DG) effectively suppressed the expression of TNF and/or IL1β in macrophages. Exosomes loaded with ASO-TNF or 2DG were able to suppress the expression of TNF and/or IL1β in macrophages in vitro or in vivo. Furthermore, infusion of Exo/ASO-TNF or Exo/2DG significantly attenuated experimental steatohepatitis in choline deficient amino acid-defined (CDAA) or methionine and choline deficient (MCD) diet-fed mice. RNA-seq results showed that treatment with Exo/ASO-TNF or Exo/2DG significantly inhibited pro-inflammatory signaling pathways. Mechanistically, we observed that administration of Exo/ASO-TNF or Exo/2DG could attenuate NASH progression by up-regulating the expression of superoxide dismutase 1 (Sod1). Combined, our findings demonstrated that infusion of exosomes loaded with ASO-TNF or 2DG alleviated experimental steatohepatitis in murine models. Thus, infusion of exosomes loaded with anti-inflammatory agents holds promise as a potential therapeutic strategy for NASH treatment.

Pharmacological treatment for metabolic dysfunction-associated steatotic liver disease and related disorders: Current and emerging therapeutic options

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly known as nonalcoholic fatty liver disease) is a chronic liver disease affecting over a billion individuals worldwide. MASLD can gradually develop into more severe liver pathologies, including metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and liver malignancy. Notably, although being a global health problem, there are very limited therapeutic options against MASLD and its related diseases. While a thyroid hormone receptor agonist (resmetirom) is recently approved for MASH treatment, other efforts to control these diseases remain unsatisfactory. Given the projected rise in MASLD and MASH incidence, it is urgent to develop novel and effective therapeutic strategies against these prevalent liver diseases. In this article, the pathogenic mechanisms of MASLD and MASH, including insulin resistance, dysregulated nuclear receptor signaling, and genetic risk factors (eg, patatin-like phospholipase domain-containing 3 and hydroxysteroid 17-β dehydrogenase-13), are introduced. Various therapeutic interventions against MASH are then explored, including approved medication (resmetirom), drugs that are currently in clinical trials (eg, glucagon-like peptide 1 receptor agonist, fibroblast growth factor 21 analog, and PPAR agonist), and those failed in previous trials (eg, obeticholic acid and stearoyl-CoA desaturase 1 antagonist). Moreover, given that the role of gut microbes in MASLD is increasingly acknowledged, alterations in the gut microbiota and microbial mechanisms in MASLD development are elucidated. Therapeutic approaches that target the gut microbiota (eg, dietary intervention and probiotics) against MASLD and related diseases are further explored. With better understanding of the multifaceted pathogenic mechanisms, the development of innovative therapeutics that target the root causes of MASLD and MASH is greatly facilitated. The possibility of alleviating MASH and achieving better patient outcomes is within reach. SIGNIFICANCE STATEMENT: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide, and it can progress to more severe pathologies, including steatohepatitis, cirrhosis, and liver cancer. Better understanding of the pathogenic mechanisms of these diseases has facilitated the development of innovative therapeutic strategies. Moreover, increasing evidence has illustrated the crucial role of gut microbiota in the pathogenesis of MASLD and related diseases. It may be clinically feasible to target gut microbes to alleviate MASLD in the future.

Deficiency of hepatokine orosomucoid1 aggravates NAFLD progression in mice

Orosomucoid (ORM) is an important hepatokine that regulates metabolism. Previous report showed that isoform ORM2 but not ORM1 could downregulate lipogenic genes and ameliorate hepatic steatosis in obese mice, thereby categorizing ORM2 as a promising candidate for therapeutic intervention in nonalcoholic fatty liver disease (NAFLD). However, our previous studies found that mice lacking ORM1 gradually developed an obese phenotype with severe hepatic steatosis at the age of 24 weeks. Consequently, it remains imperative to further investigate the precise role of ORM1 in the context of NAFLD. The current study aims to assess the function and therapeutic prospects of ORM1 in NAFLD models induced by a high-fat diet (HFD) or a methionine- and choline-deficient diet (MCD), employing a series of loss- and gain-of-function experiments. The results showed that liver ORM levels elevated in fat NAFLD models but decreased in lean NAFLD models. Orm1-deficient mice fed either on HFD or MCD had significantly higher NAFLD activity score with more severe steatosis and ballooning, showing an aggravated NAFLD progression. However, liver-specific Orm1 overexpression in mice could not alleviate NAFLD when fed on HFD or MCD. These results suggest that systemic endogenous ORM1 is indispensable in protecting against the development of NAFLD; however, it may not serve as an effective localized therapeutic target for managing the disease.

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

Preparation of Morchella esculenta protein and its preventive effect on nonalcoholic fatty liver disease in mice

Morchella esculenta is a valuable edible fungus with multidimensional bioactivities; however, research on M. esculenta protein and its beneficial effects on nonalcoholic fatty liver disease (NAFLD) have been limited. In this study, M. esculenta protein (MEP) with 80.59% protein content was prepared, isolated, and characterized by the complete amino acid composition. The main molecular weight of the protein ranged from 65 to 120 kDa, with 100 kDa being the most dominant band, and it exhibited an alpha helix structure when analyzed by FT-IR and circular dichroism analysis. MEP could regulate body weight, fat accumulation, and alleviate lipid metabolism in adipose tissues in mice with high-fat diet-induced NAFLD. MEP prevented hepatic lipotoxicity, which was reflected in attenuating liver steatosis in vitro and in vivo, thereby regulating the levels of related factors involved in lipid metabolism (e.g., PPARs, HNF-4, SREBP, FASN, ACC-1, and CD36). Furthermore, it inhibited oxidative stress response, which can be attributed to the activation of the MAPK/PGC-1α pathway. Additionally, MEP exhibited probiotic effects, as demonstrated by the altered gut microbiota composition and improved the intestinal barrier integrity. Thus, this study confirmed the preventive effect of MEP against NAFLD by regulating the gut-liver cross-talk, which provided a theoretical basis for the development and utilization of M. esculenta.

Polydatin retards the progression of osteoarthritis by maintaining bone metabolicbalance and inhibiting macrophage polarization

Background

Polydatin (PD), also known as tiger cane glycoside, is a natural compound extracted from the Japanese knotweed plant, which is often referred to as white resveratrol. It exhibits anti-inflammatory, antioxidant, and anti-apoptotic effects in the treatment of various diseases. However, the potential molecular mechanisms of PD in osteoarthritis have not been clearly elucidated.

Methods

Anterior cruciate ligament transection (ACLT) surgery was performed to establish an osteoarthritis animal model. Female mice at the age of 12 weeks were intraperitoneally injected with different concentrations of PD (20 and 40 mg/kg). In vitro models were established by isolating mouse articular chondrocytes, which were subsequently treated with lipopolysaccharide or IL-1β for 24 h for subsequent experiments. In addition, different concentrations of PD were administered for 12 h. Morphological changes were observed by toluidine blue staining, joint bone metabolism changes were observed by tartrate-resistant acid phosphatase staining, immunohistochemistry was used to observe the expression levels of inflammatory factors and extracellular matrix. MicroCT analysis was conducted to assess changes in the microstructure of subchondral bone trabeculae, and Western blot was performed to measure the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway and markers of M1 polarization in macrophages.

Results

PD significantly delays the progression of osteoarthritis induced by ACLT, effectively inhibits IL-1β-induced joint inflammation, bone metabolic remodeling and extracellular matrix degradation. In addition, paeoniflorin markedly suppresses the transmission of the NF-κB signaling pathway and reverses M1 polarization in macrophages induced by IL-1β.

Conclusion

Taken together, PD might be a potential therapeutic agent for the prevention and treatment of osteoarthritis.

Inappropriate Diet Exacerbates Metabolic Dysfunction-Associated Steatotic Liver Disease via Abdominal Obesity

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a refined categorization of non-alcoholic fatty liver disease (NAFLD), highlighting the intricate relationship between hepatic steatosis and metabolic dysfunction. Abdominal obesity (AO), a key diagnostic criterion for metabolic dysfunction, predominantly results from inappropriate diet and unhealthy dietary habits. To comprehensively investigate which dietary factors contribute to MASLD through AO and to understand the underlying biological mechanisms, we initially conducted a systematic review of meta-analysis articles in the PubMed database from the past decade, summarizing dietary factors that affect AO. Subsequently, we conducted targeted searches in the PubMed database for these dietary factors and provided a narrative review of the mechanisms of how these dietary factors lead to AO and how AO exacerbates MASLD. A diet characterized by excessive intake of energy, carbohydrates, fructose, or ultra-processed foods (UPFs) is considered inappropriate. Inappropriate diet leads to the formation of MASLD and AO by enhancing pathways such as de novo lipid synthesis (DNL) in the liver, insulin resistance (IR), gut-liver dysfunction, and inflammation. Dietary interventions for inappropriate diets can effectively intervene in and improve MASLD and AO. The mechanism of inappropriate diet on abdominal fat deposition is through excessive energy or the activation of the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) to increase endocortisol secretion. Then, the excessive accumulation of visceral fat facilitates a rapid and augmented flux of free fatty acids (FFAs) to the liver and initiates a series of deleterious effects, including oxidative stress (OS), endoplasmic reticulum stress (ERS), activation of protein kinase C (PKC) pathways, and inflammation. Additionally, FFAs may mediate excessive lipid deposition and hepatocellular damage through the action of hormones. These pathways to liver damage exacerbate MASLD and progression to metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis. Furthermore, investigating other potential mechanisms by which AO may influence MASLD could offer new recommendations for the treatment guidelines of MASLD.

Role of Peptidyl Arginine Deiminase 4-Dependent Macrophage Extracellular Trap Formation in Type 1 Diabetes Pathogenesis

Excessive formation of macrophage extracellular trap (MET) has been implicated in several autoimmune disease pathogeneses; however, its impact on type 1 diabetes (T1D) and related mechanisms remains enigmatic. We demonstrated the pivotal role of peptidyl arginine deiminase 4 (PAD4) in driving profuse MET formation and macrophage M1 polarization in intestinal inflammation in NOD mice. Genetic knockout of PAD4 or adoptive transfer of METs altered the proportion of proinflammatory T cells in the intestine, subsequently influencing their migration to the pancreas. Combining RNA sequencing and CUT&Tag analysis, we found activated PAD4 transcriptionally regulated CXCL10 expression. This study comprehensively investigated how excessive PAD4-mediated MET formation in the colon increases the aggravation of intestinal inflammation and proinflammatory T-cell migration and finally is involved in T1D progression, suggesting that inhibition of MET formation may be a potential therapeutic target in T1D.

ARTICLE HIGHLIGHTS

Metabolic obesity phenotypes and the risk of cancer: a prospective study of the Kailuan cohort

Background

Obesity is as an important risk factor for chronic diseases. Metabolically healthy obesity (MHO) is considered a benign state. The association between metabolic health and obesity categories and cancer risk remains unclear. This study aimed to investigate the relationship between metabolic health status combined with obesity phenotypes and the risk of cancer.

Methods

Data from 91,834 participants in the Kailuan cohort were analyzed, excluding individuals with a body mass index (BMI) < 18.5 kg/m² and those with a history of cancer. Obesity phenotypes were classified based on BMI and waist circumference (WC) combined with metabolic health status, resulting in six phenotypes. Cox proportional hazard regression models were used to assess the association between metabolic health and obesity phenotypes with cancer risk and all-cause mortality.

Results

The prevalence of metabolically healthy obesity and metabolically unhealthy obesity defined by BMI was 6.86% and 12.18%, while that defined by WC was 20.79% and 25.76%, respectively. Compared to metabolically healthy participants, individuals with an unhealthy metabolic status had a significantly higher risk of cancer (HR, 1.09; 95% CI, 1.03-1.15; p=0.004). The hazard ratios for cancer were 1.19, 1.23, 1.20, and 1.55 for individuals with one, two, three, and four metabolic disorders, respectively. Among those classified as metabolically unhealthy, both overweight and obesity were associated with a protective effect on cancer risk (HR, 0.88; 95% CI, 0.80-0.96; p=0.006 for overweight; HR, 0.87; 95% CI, 0.78-0.97; p=0.010 for obesity). However, abdominal obesity significantly increased cancer risk in both metabolically healthy and unhealthy participants. In subgroup analysis, simple obesity showed a protective trend against cancer in those with respiratory cancers, while abdominal obesity consistently posed a risk for various cancer types.

Conclusion

Metabolically unhealthy status and abdominal obesity are risk factors for cancer and all-cause mortality, whereas simple obesity offers protective effects against cancer and all-cause mortality in metabolically unhealthy individuals. These findings suggest that maintaining metabolic health and reducing the metabolic risks associated with abdominal obesity should be key targets for cancer prevention.

Thermal ablation enhances immunotherapeutic effect of IP-001 on orthotopic liver cancer in a rat model

BACKGROUND

Thermal ablation is reported to increase immunogenicity in tumor cells via expressing tumor antigens. IP-001, a synthesized molecule, is created by attaching galactose molecules to the free amino groups of partially deacetylated glucosamine polymers. As a member of a new class of polycationic immunoadjuvants that activate multiple immune response pathways, IP-001 can both sequester ablation-released tumor antigens in situ and independently recruit and stimulate antigen presenting cells (APCs) to induce a potent tumor-specific Th1 type T cell response.

METHODS

An orthotopic HCC rat model is established by implantation of 5 × 106 N1-S1 cells into the left lobe of liver. When tumor size reached 1.0-1.5 cm3, the animals were divided randomly into 4 groups, (1) MWA+IP-001; (2) MWA+saline; (3) sham MWA+IP-001 and (4) sham MWA+saline (n = 5 each group).

RESULTS

IP001 + MWA treatment significantly suppressed tumor growth in comparison to the other 3 groups. Significantly increased infiltration of inflammatory/immune cells were found in the tumor adjacent tissues of MWA+IP-001 mice, compared to the other 3 groups. Flow cytometry results indicated that there were significant increases of cytotoxic T cells, macrophages, dendritic cells and NK cell in the combination of MWA and IP001 treated mice, compared to other 3 groups (p < 0.01). Significantly decreased number of Treg cells were found in all the treatment arms compared to untreated control (p < 0.01).

CONCLUSION

Combination of MWA and IP001 enhances tumor suppression in an orthotopic HCC rat model. The tumor suppression is associated to the enhanced immune responses in terms of recruiting the important cell subpopulations such as CD8 + T-cells and NK cells into tumor microenvironment and abolishing immune suppressor such as Treg cells.

Progress in the Study of Animal Models of Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) has recently been proposed as an alternative term to NAFLD. MASLD is a globally recognized chronic liver disease that poses significant health concerns and is frequently associated with obesity, insulin resistance, and hyperlipidemia. To better understand its pathogenesis and to develop effective treatments, it is essential to establish suitable animal models. Therefore, attempts have been made to establish modelling approaches that are highly similar to human diet, physiology, and pathology to better replicate disease progression. Here, we reviewed the pathogenesis of MASLD disease and summarised the used animal models of MASLD in the last 7 years through the PubMed database. In addition, we have summarised the commonly used animal models of MASLD and describe the advantages and disadvantages of various models of MASLD induction, including genetic models, diet, and chemically induced models, to provide directions for research on the pathogenesis and treatment of MASLD.

Deletion of p38 MAPK in macrophages ameliorates peritoneal fibrosis and inflammation in peritoneal dialysis

One of the most common causes of peritoneal dialysis withdrawal is ultrafiltration failure which is characterized by peritoneal membrane thickening and fibrosis. Although previous studies have demonstrated the inhibitory effect of p38 MAPK inhibitors on peritoneal fibrosis in mice, it was unclear which specific cells contribute to peritoneal fibrosis. To investigate the role of p38 MAPK in peritoneal fibrosis more precisely, we examined the expression of p38 MAPK in human peritoneum and generated systemic inducible p38 MAPK knockout mice and macrophage-specific p38 MAPK knockout mice. Furthermore, the response to lipopolysaccharide (LPS) was assessed in p38 MAPK-knocked down RAW 264.7 cells to further explore the role of p38 MAPK in macrophages. We found that phosphorylated p38 MAPK levels were increased in the thickened peritoneum of both human and mice. Both chlorhexidine gluconate (CG)-treated systemic inducible and macrophage-specific p38 MAPK knockout mice ameliorated peritoneal thickening, mRNA expression related to inflammation and fibrosis, and the number of αSMA- and MAC-2-positive cells in the peritoneum compared to CG control mice. Reduction of p38 MAPK in RAW 264.7 cells suppressed inflammatory mRNA expression induced by LPS. These findings suggest that p38 MAPK in macrophages plays a critical role in peritoneal inflammation and thickening.

Targeting hepatic macrophages for non-alcoholic fatty liver disease therapy

Non-alcoholic fatty liver disease (NAFLD) and its more advanced form, non-alcoholic steatohepatitis (NASH), have become global health challenges with significant morbidity and mortality rates. NAFLD encompasses several liver diseases, ranging from simple steatosis to more severe inflammatory and fibrotic forms. Ultimately, this can lead to liver cirrhosis and hepatocellular carcinoma. The intricate role of hepatic macrophages, particularly Kupffer cells (KCs) and monocyte-derived macrophages (MoMFs), in the pathogenesis of NAFLD and NASH, has received increasing attention. Hepatic macrophages can interact with hepatocytes, hepatic stellate cells, and endothelial cells, playing a crucial role in maintaining homeostasis. Paradoxically, they also participate in the pathogenesis of some liver diseases. This review highlights the fundamental role of hepatic macrophages in the pathogenesis of NAFLD and NASH, emphasizing their plasticity and contribution to inflammation and fibrosis, and hopes to provide ideas for subsequent experimental research and clinical treatment.

Fatty acids promote M1 polarization of monocyte-derived macrophages in healthy or ketotic dairy cows and a bovine macrophage cell line by impairing mTOR-mediated autophagy

Excessive concentrations of free fatty acids (FFA) are the main factors causing immune dysfunction and inflammation in dairy cows with ketosis. Polarization of macrophages (the process of macrophages freely switching from one phenotype to another) into M1 or M2 phenotypes is an important event during inflammation induced by environmental stimuli. In nonruminants, mammalian target of rapamycin (mTOR)-mediated autophagy (a major waste degradation process) regulates macrophage polarization. Thus, our objective was to unravel the role of mTOR-mediated autophagy on macrophage polarization in ketotic dairy cows. We performed 4 experiments: (1) In vitro differentiated monocyte-derived macrophages from healthy dairy cows or dairy cows with clinical ketosis (CK) were treated for 24 h with 100 ng/mL LPS and 100 ng/mL IFN-γ or with 10 ng/mL IL4 and 10 ng/mL IL10; (2) Immortalized bovine macrophages were treated for 24 h with 0, 0.3, 0.6, or 1.2 mM FFA, LPS, and IFN-γ, or with IL4 and IL10; (3) Macrophages were pretreated with 2 μM 4,6-dimorpholino-N-(4-nitrophenyl)-1,3,5-triazin-2-amine (MHY1485) for 30 min before treatment with LPS and IFN-γ or IL4 and IL10; (4) Macrophages were pretreated with 100 nM rapamycin (RAPA) for 2 h before treatment with LPS and IFN-γ or IL4 and IL10. Compared with healthy cows, cows with CK had a greater mean fluorescence intensity (MFI) of CD86+, but lower MFI of CD206+ and lower number of autophagosomes and autolysosomes in macrophages. Exogenous FFA treatment upregulated protein abundance of inducible nitric oxide synthase (iNOS) and the MFI of CD86, whereas it downregulated the protein abundance of arginase 1 and the MFI of CD206. In addition, FFA increased the p-p65/p65 protein abundance and tumor necrosis factor α, IL1B, and IL6 mRNA abundance, but decreased LC3-phosphatidylethanolamine conjugate protein abundance and the number of autophagosomes and autolysosomes number. Pretreatment with MHY1485 promoted macrophage M1 polarization and inhibited macrophage M2 polarization via decreased mTOR-mediated autophagy. Activation of mTOR-mediated autophagy by pretreatment with RAPA attenuated the upregulation of inflammation in M1 macrophages that was induced by FFA. These data revealed that high concentrations of FFA promote macrophage M1 polarization in ketotic dairy cows by impairing mTOR-mediated autophagy.

Irradiated tumor cell-released microparticles enhance the therapeutic efficacy of PD-1 inhibitors by promoting M1-TAMs polarization in NSCLC brain metastases

Brain metastases (BMs) are the most common sites of metastasis in patients with non-small cell lung cancer (NSCLC). However, BMs are not responsive to immunotherapy because of the blood-brain barrier. This is because intracranial immune cells such as M2 tumor-associated macrophages (TAMs) accumulate, creating an immunosuppressive tumor microenvironment. In this study, we focused on irradiated tumor cell-released microparticles (RT-MPs) that can cross the blood-brain barrier and influence the intracranial immune microenvironment. Using animal models of BMs, we observed that RT-MPs could penetrate the blood-brain barrier and be swallowed by TAMs. Then the microenvironment of TAMs is shifted from the M2 phenotype to the M1 phenotype, thereby modulating the interactions between TAMs and tumor cells. Single-cell sequencing analysis demonstrated that TAMs, after internalizing RT-MPs, active chemokine signaling pathways and secrete more chemokines, such as CCL5, CXCL2, CXCL1, CCL3, CCL4, and CCL22, attracting more CD4+ T cells and CD8+ T cells, improving immune-mediated killing, and enhancing subsequent combination anti-PD-1 therapy. These findings provide a preclinical foundation for exploring alternative treatments for patients with immunoresistant NSCLC BMs.

Tanshinone IIA Inhibits the Endoplasmic Reticulum Stress-Induced Unfolded Protein Response by Activating the PPARα/FGF21 Axis to Ameliorate Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a critical stage in the progression of nonalcoholic fatty liver disease (NAFLD). Tanshinone IIA (TIIA) is a tanshinone extracted from Salvia miltiorrhiza; due to its powerful anti-inflammatory and antioxidant biological activities, it is commonly used for treating cardiovascular and hepatic diseases. A NASH model was established by feeding mice a methionine and choline-deficient (MCD) diet. Liver surface microblood flow scanning, biochemical examination, histopathological examination, cytokine analysis through ELISA, lipidomic analysis, transcriptomic analysis, and Western blot analysis were used to evaluate the therapeutic effect and mechanism of TIIA on NASH. The results showed that TIIA effectively reduced lipid accumulation, fibrosis, and inflammation and alleviated endoplasmic reticulum (ER) stress. Lipidomic analysis revealed that TIIA normalized liver phospholipid metabolism in NASH mice. A KEGG analysis of the transcriptome revealed that TIIA exerted its effect by regulating the PPAR signalling pathway, protein processing in the ER, and the NOD-like receptor signalling pathway. These results suggest that TIIA alleviates NASH by activating the PPARα/FGF21 axis to negatively regulate the ER stress-induced unfolded protein response (UPR).

Exploring the possible therapeutic mechanism of Danzhixiaoyao pills in depression and MAFLD based on "Homotherapy for heteropathy": A network pharmacology and molecular docking

Objective

Danzhixiaoyao pills (DXP) is a traditional Chinese medicine formula that has been effectively used in clinical practice to treat depression and metabolic associated fatty liver disease (MAFLD), but its therapeutic mechanism is not yet clear. The purpose of this study is to explore the possible mechanisms of DXP in treating depression and MAFLD using network pharmacology and molecular docking techniques based on existing literature reports.

Methods

By combining TCMSP, Swiss ADME, Swiss TargetPrediction, and UniProt databases, the active ingredients and potential targets of DXP were screened and obtained. By searching for relevant disease targets through Gene Cards, OMIM, and TTD databases, intersection targets between drugs and diseases were obtained. The network of "Disease - Potential targets - Active ingredients - Traditional Chinese medicine - Prescriptions" was constructed using Cytoscape 3.9.1 software, and the PPI network was constructed using STRING 12.0 database. The core targets were obtained through topology analysis. GO function enrichment and KEGG pathway enrichment analysis were conducted based on DAVID. The above results were validated by molecular docking using PyMol 2.5 and AutoDock Tool 1.5.7 software, and their possible therapeutic mechanisms were discussed.

Results

Network pharmacology analysis obtained 130 main active ingredients of drugs, 173 intersection targets between drugs and diseases, and 37 core targets. Enrichment analysis obtained 1390 GO functional enrichment results, of which 922 were related to biological process, 107 were related to cellular component, 174 were related to molecular function, and obtained 180 KEGG pathways. Molecular docking has confirmed the good binding ability between relevant components and targets, and the literature discussion has preliminarily verified the above results.

Conclusion

DXP can act on targets such as TNF, AKT1, ALB, IL1B, TP53 through active ingredients such as kaempferol, quercetin, naringenin, isorhamnetin, glyuranolide, etc, and by regulating signaling pathways such as pathways in cancer, MAPK signaling pathway, lipid and atherosclerosis, to exert its effect of "homotherapy for heteropathy" on depression and MAFLD. In addition, glyuranolide showed the strongest affinity with TNF (-7.88 kcal/mol), suggesting that it may play a key role in the treatment process. The research results provide a theoretical basis for elucidating the scientific connotation and mechanism of action of traditional Chinese medicine compound DXP, and provide new directions for its clinical application.

Reactive oxygen species regulation by NCF1 governs ferroptosis susceptibility of Kupffer cells to MASH

Impaired self-renewal of Kupffer cells (KCs) leads to inflammation in metabolic dysfunction-associated steatohepatitis (MASH). Here, we identify neutrophil cytosolic factor 1 (NCF1) as a critical regulator of iron homeostasis in KCs. NCF1 is upregulated in liver macrophages and dendritic cells in humans with metabolic dysfunction-associated steatotic liver disease and in MASH mice. Macrophage NCF1, but not dendritic cell NCF1, triggers KC iron overload, ferroptosis, and monocyte-derived macrophage infiltration, thus aggravating MASH progression. Mechanistically, elevated oxidized phospholipids induced by macrophage NCF1 promote Toll-like receptor (TLR4)-dependent hepatocyte hepcidin production, leading to increased KC iron deposition and subsequent KC ferroptosis. Importantly, the human low-functional polymorphic variant NCF190H alleviates KC ferroptosis and MASH in mice. In conclusion, macrophage NCF1 impairs iron homeostasis in KCs by oxidizing phospholipids, triggering hepatocyte hepcidin release and KC ferroptosis in MASH, highlighting NCF1 as a therapeutic target for improving KC fate and limiting MASH progression.

Single-cell sequencing combined with spatial transcriptomics reveals that the IRF7 gene in M1 macrophages inhibits the occurrence of pancreatic cancer by regulating lipid metabolism-related mechanisms

AIM

The main focus of this study is to explore the molecular mechanism of IRF7 regulation on RPS18 transcription in M1-type macrophages in pancreatic adenocarcinoma (PAAD) tissue, as well as the transfer of RPS18 by IRF7 via exosomes to PAAD cells and the regulation of ILF3 expression.

METHODS

By utilising single-cell RNA sequencing (scRNA-seq) data and spatial transcriptomics (ST) data from the Gene Expression Omnibus database, we identified distinct cell types with significant expression differences in PAAD tissue. Among these cell types, we identified those closely associated with lipid metabolism. The differentially expressed genes within these cell types were analysed, and target genes relevant to prognosis were identified. Flow cytometry was employed to assess the expression levels of target genes in M1 and M2 macrophages. Cell lines with target gene knockout were constructed using CRISPR/Cas9 editing technology, and cell lines with target gene knockdown and overexpression were established using lentiviral vectors. Additionally, a co-culture model of exosomes derived from M1 macrophages with PAAD cells was developed. The impact of M1 macrophage-derived exosomes on the lipid metabolism of PAAD cells in the model was evaluated through metabolomics analysis. The effects of M1 macrophage-derived exosomes on the viability, proliferation, division, migration and apoptosis of PAAD cells were assessed using MTT assay, flow cytometry, EdU assay, wound healing assay, Transwell assay and TUNEL staining. Furthermore, a mouse PAAD orthotopic implantation model was established, and bioluminescence imaging was utilised to assess the influence of M1 macrophage-derived exosomes on the intratumoural formation capacity of PAAD cells, as well as measuring tumour weight and volume. The expression of proliferation-associated proteins in tumour tissues was examined using immunohistochemistry.

RESULTS

Through combined analysis of scRNA-seq and ST technologies, we discovered a close association between M1 macrophages in PAAD samples and lipid metabolism signals, as well as a negative correlation between M1 macrophages and cancer cells. The construction of a prognostic risk score model identified RPS18 and IRF7 as two prognostically relevant genes in M1 macrophages, exhibiting negative and positive correlations, respectively. Mechanistically, it was found that IRF7 in M1 macrophages can inhibit the transcription of RPS18, reducing the transfer of RPS18 to PAAD cells via exosomes, consequently affecting the expression of ILF3 in PAAD cells. IRF7/RPS18 in M1 macrophages can also suppress lipid metabolism, cell viability, proliferation, migration, invasion and intratumoural formation capacity of PAAD cells, while promoting cell apoptosis.

CONCLUSION

Overexpression of IRF7 in M1 macrophages may inhibit RPS18 transcription, reduce the transfer of RPS18 from M1 macrophage-derived exosomes to PAAD cells, thereby suppressing ILF3 expression in PAAD cells, inhibiting the lipid metabolism pathway, and curtailing the viability, proliferation, migration, invasion of PAAD cells, as well as enhancing cell apoptosis, ultimately inhibiting tumour formation in PAAD cells in vivo. Targeting IRF7/RPS18 in M1 macrophages could represent a promising immunotherapeutic approach for PAAD in the future.

Progranulin: A promising biomarker and therapeutic target for fibrotic diseases

Progranulin (PGRN), a multifunctional growth factor-like protein expressed by a variety of cell types, serves an important function in the physiologic and pathologic processes of fibrotic diseases, including wound healing and the inflammatory response. PGRN was discovered to inhibit pro-inflammation effect by competing with tumor necrosis factor-alpha (TNF-α) binding to TNF receptors. Notably, excessive tissue repair in the development of inflammation causes tissue fibrosis. Previous investigations have indicated the significance of PGRN in regulating inflammatory responses. Recently, multiple studies have shown that PGRN was linked to fibrogenesis, and was considered to monitor the formation of fibrosis in multiple organs, including liver, cardiovascular, lung and skin. This paper is a comprehensive review summarizing our current knowledge of PGRN, from its discovery to the role in fibrosis. This is followed by an in-depth look at the characteristics of PGRN, consisting of its structure, basic function and intracellular signaling. Finally, we will discuss the potential of PGRN in the diagnosis and treatment of fibrosis.

Identification and Validation of CXCL2 as a Key Gene for Childhood Obesity

This study aims to identify the key genes and their regulatory networks by bioinformatics, increasing understanding of childhood obesity. The data comes from the GEO and Immport database. The immune microenvironment was explored in GSE104815. Key genes were identified by intersection of DEGs with the immune gene set. Enrichment analysis revealed gene-related functions and correlation analysis explored the relationship. Regulatory networks were constructed based on miRcode, TarBase and TargetScan databases. GSE29718 was used to validate our findings. Intercellular communication and cell differentiation trends were further explored using single-cell data from GSE153643. Based on our research, the immune microenvironment in the obese group showed higher immune infiltration. We found 962 DEGs and CXCL2 was identified as the key gene. The co-regulatory network of lncRNA-miRNA-mRNA suggested that obtaining TM4SF19-AS1, GUSBP11, AC105020.1, LINC00189, COL4A2-AS2, VIPR1-AS1 and LINC00242 may regulate CXCL2 (r > 0.9 and P < 0.01). Differential expression of CXCL2 was validated in GSE29718 (P < 0.05) and CXCL2 was identified as a biomarker for childhood obesity (AUC = 0.885). GSVA enrichment analysis revealed many pathways of high group obtaining the TNF-α signaling via NF-κB pathway and interferon γ response pathway. In GSE153643, 11 cell types were identified and CXCL2 was highly expressed in monocyte, macrophage, endothelial cell and pericyte. In CXCL2 high expressing macrophages, there was a tendency for cells to polarize toward M1 macrophages (P < 0.05). In summary, we identified CXCL2 as a potential biomarker of childhood obesity. The development of childhood obesity may be associated with the activation of immune infiltration of macrophage M1 polarization by CXCL2 expression.

HDAC6 inhibitor ACY-1215 protects from nonalcoholic fatty liver disease via inhibiting CD14/TLR4/MyD88/MAPK/NFκB signal pathway

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by hepatic steatosis, for which there is currently no effective treatment. ACY-1215 is a selective inhibitor of histone deacetylation 6, which has shown therapeutic potential in many tumors, as well as acute liver injury. However, no research about ACY-1215 on NAFLD has been published. Therefore, our study aims to explore the role and mechanism of ACY-1215 in the experimental model of NAFLD, to propose a new treatment strategy for NAFLD.

METHODS

We established cell and animal models of NAFLD and verified the effect of ACY-1215 on NAFLD. The mechanism of ACY-1215 on NAFLD was preliminarily explored through TMT relative quantitative proteomics, and then we verify the mechanism discovered in the experimental model of NAFLD.

RESULTS

ACY-1215 can reduce lipid aggregation, IL-1β, and TNF α mRNA levels in liver cells in vitro. ACY-1215 can reduce the weight gain and steatosis in the liver of the NAFLD mouse model, alleviate the deterioration of liver function, and reduce IL-1βs and TNF α mRNA levels in hepatocytes. TMT relative quantitative proteomics found that ACY-1215 decreased the expression of CD14 in hepatocytes. It was found that ACY-1215 can inhibit the activation level of CD14/TLR4/MyD88/MAPK/NFκB pathway in the NAFLD experimental model.

CONCLUSIONS

ACY-1215 has a protective effect on the cellular model of NAFLD induced by fatty acids and lipopolysaccharide, as well as the C57BL/6J mouse model induced by a high-fat diet. ACY-1215 may play a protective role by inhibiting CD14/TLR4/MyD88/MAPK/NFκB signal pathway.

Molecular characteristics and immune microenvironment of gastrointestinal stromal tumours: targets for therapeutic strategies

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours, arising mainly from the interstitial cells of Cajal (ICCs) of the gastrointestinal tract. As radiotherapy and chemotherapy are generally ineffective for GISTs, the current primary treatment is surgical resection. However, surgical resection is not choice for most patients. Therefore, new therapeutic strategies are urgently needed. Targeted therapy, represented by tyrosine kinase inhibitors (TKIs), and immunotherapy, represented by immune checkpoint inhibitor therapies and chimeric antigen receptor T-cell immunotherapy (CAR-T), offer new therapeutic options in GISTs and have shown promising treatment responses. In this review, we summarize the molecular classification and immune microenvironment of GISTs and discuss the corresponding targeted therapy and immunotherapy options. This updated knowledge may provide more options for future therapeutic strategies and applications in GISTs.

Ferroptosis: principles and significance in health and disease

Ferroptosis, an iron-dependent form of cell death characterized by uncontrolled lipid peroxidation, is governed by molecular networks involving diverse molecules and organelles. Since its recognition as a non-apoptotic cell death pathway in 2012, ferroptosis has emerged as a crucial mechanism in numerous physiological and pathological contexts, leading to significant therapeutic advancements across a wide range of diseases. This review summarizes the fundamental molecular mechanisms and regulatory pathways underlying ferroptosis, including both GPX4-dependent and -independent antioxidant mechanisms. Additionally, we examine the involvement of ferroptosis in various pathological conditions, including cancer, neurodegenerative diseases, sepsis, ischemia-reperfusion injury, autoimmune disorders, and metabolic disorders. Specifically, we explore the role of ferroptosis in response to chemotherapy, radiotherapy, immunotherapy, nanotherapy, and targeted therapy. Furthermore, we discuss pharmacological strategies for modulating ferroptosis and potential biomarkers for monitoring this process. Lastly, we elucidate the interplay between ferroptosis and other forms of regulated cell death. Such insights hold promise for advancing our understanding of ferroptosis in the context of human health and disease.

Lack of p38 activation in T cells increases IL-35 and protects against obesity by promoting thermogenesis

Obesity is characterized by low-grade inflammation, energy imbalance and impaired thermogenesis. The role of regulatory T cells (Treg) in inflammation-mediated maladaptive thermogenesis is not well established. Here, we find that the p38 pathway is a key regulator of T cell-mediated adipose tissue (AT) inflammation and browning. Mice with T cells specifically lacking the p38 activators MKK3/6 are protected against diet-induced obesity, leading to an improved metabolic profile, increased browning, and enhanced thermogenesis. We identify IL-35 as a driver of adipocyte thermogenic program through the ATF2/UCP1/FGF21 pathway. IL-35 limits CD8+ T cell infiltration and inflammation in AT. Interestingly, we find that IL-35 levels are reduced in visceral fat from obese patients. Mechanistically, we demonstrate that p38 controls the expression of IL-35 in human and mouse Treg cells through mTOR pathway activation. Our findings highlight p38 signaling as a molecular orchestrator of AT T cell accumulation and function.

The signaling pathways in obesity-related complications

Obesity, a rapidly expanding epidemic worldwide, is known to exacerbate many medical conditions, making it a significant factor in multiple diseases and their associated complications. This threatening epidemic is linked to various harmful conditions such as type 2 diabetes mellitus, hypertension, metabolic dysfunction-associated steatotic liver disease, polycystic ovary syndrome, cardiovascular diseases (CVDs), dyslipidemia, and cancer. The rise in urbanization and sedentary lifestyles creates an environment that fosters obesity, leading to both psychosocial and medical complications. To identify individuals at risk and ensure timely treatment, it is crucial to have a better understanding of the pathophysiology of obesity and its comorbidities. This comprehensive review highlights the relationship between obesity and obesity-associated complications, including type 2 diabetes, hypertension, (CVDs), dyslipidemia, polycystic ovary syndrome, metabolic dysfunction-associated steatotic liver disease, gastrointestinal complications, and obstructive sleep apnea. It also explores the potential mechanisms underlying these associations. A thorough analysis of the interplay between obesity and its associated complications is vital in developing effective therapeutic strategies to combat the exponential increase in global obesity rates and mitigate the deadly consequences of this polygenic condition.

SLC7A11-ROS/αKG-AMPK axis regulates liver inflammation through mitophagy and impairs liver fibrosis and NASH progression

The changes of inflammation and metabolism are two features in nonalcoholic steatohepatitis (NASH). However, how they interact to regulate NASH progression remains largely unknown. Our works have demonstrated the importance of solute carrier family 7 member 11 (SLC7A11) in inflammation and metabolism. Nevertheless, whether SLC7A11 regulates NASH progression through mediating inflammation and metabolism is unclear. In this study, we found that SLC7A11 expression was increased in liver samples from patients with NASH. Upregulated SLC7A11 level was also detected in two murine NASH models. Functional studies showed that SLC7A11 knockdown or knockout had augmented steatohepatitis with suppression of inflammatory markers in mice. However, overexpression of SLC7A11 dramatically alleviated diet-induced NASH pathogenesis. Mechanically, SLC7A11 decreased reactive oxygen species (ROS) level and promoted α-ketoglutarate (αKG)/prolyl hydroxylase (PHD) activity, which activated AMPK pathway. Furthermore, SLC7A11 impaired expression of NLRP3 inflammasome components through AMPK-mitophagy axis. IL-1β release through NLRP3 inflammasome recruited myeloid cells and promoted hepatic stellate cells (HSCs) activation, which contributed to the progression of liver injury and fibrosis. Anti-IL-1β and anakinra might attenuate the hepatic inflammatory response evoked by SLC7A11 knockdown. Moreover, the upregulation of SLC7A11 in NASH was contributed by lipid overload-induced JNK-c-Jun pathway. In conclusions, SLC7A11 acts as a protective factor in controlling the development of NASH. Upregulation of SLC7A11 is protective by regulating oxidation, αKG and energy metabolism, decreasing inflammation and fibrosis.

Gossypetin targets the liver-brain axis to alleviate pre-existing liver fibrosis and hippocampal neuroinflammation in mice

Liver fibrosis occurs in response to chronic damage and inflammation to the liver. Leaving untreated, it can lead to decreased liver function and can eventually progress to cirrhosis, a more advanced and irreversible state of liver damage. Clinical investigations showed that chronic liver disease associated with neurological symptoms including anxiety, depression, and cognitive decline. However, few therapeutic options are available for treating liver and related brain pathologies simultaneously. In this study, we aim to find therapeutic candidates that target the liver-brain axis. Gossypetin, a flavonoid from sedum, shows promising capability in treating liver and brain pathologies in CCl4-induced mouse model. Short term of gossypetin administration is sufficient to ameliorate impaired liver function and pre-existing liver fibrosis, suppress MKK3/6-p38 MAPK and p53 activation, and abolish the activation of hepatic stellate cells and Kupffer cells. Although we observe no neuronal loss in the brain of mice with liver fibrosis, we do observe astrogliosis and microglial activation in certain brain regions, especially the hippocampus. Brief gossypetin administration also shows potential in alleviating neuroinflammation in these regions. These results suggest that gossypetin can target the liver-brain axis and be a promising candidate for treating chronic liver fibrosis patients with neurological symptoms.

LECT2 Deletion Exacerbates Liver Steatosis and Macrophage Infiltration in a Male Mouse Model of LPS-mediated NASH

Leukocyte cell-derived chemotaxin 2 (LECT2) is a protein initially isolated as a neutrophil chemotactic factor. We previously found that LECT2 is an obesity-associated hepatokine that senses liver fat and induces skeletal muscle insulin resistance. In addition, hepatocyte-derived LECT2 activates macrophage proinflammatory activity by reinforcing the lipopolysaccharide (LPS)-induced c-Jun N-terminal kinase signaling. Based on these findings, we examined the effect of LECT2 deletion on nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH) caused by bacterial translocation. We created the bacterial translocation-mediated NAFLD/NASH model using LECT2 knockout mice (LECT2 KO) with 28 times a low-dose LPS injection under high-fat diet feeding conditions. LECT2 deletion exacerbated steatosis and significantly reduced p38 phosphorylation in the liver. In addition, LECT2 deletion increased macrophage infiltration with decreased M1/M2 ratios. LECT2 might contribute to protecting against lipid accumulation and macrophage activation in the liver under pathological conditions, which might be accomplished via p38 phosphorylation. This study provides novel aspects of LECT2 in the bacterial translocation-mediated NAFLD/NASH model.

Traditional Chinese medicine in regulating macrophage polarization in immune response of inflammatory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Numerous studies have demonstrated that various traditional Chinese medicines (TCMs) exhibit potent anti-inflammatory effects against inflammatory diseases mediated through macrophage polarization and metabolic reprogramming.

AIM OF THE STUDY

The objective of this review was to assess and consolidate the current understanding regarding the pathogenic mechanisms governing macrophage polarization in the context of regulating inflammatory diseases. We also summarize the mechanism action of various TCMs on the regulation of macrophage polarization, which may contribute to facilitate the development of natural anti-inflammatory drugs based on reshaping macrophage polarization.

MATERIALS AND METHODS

We conducted a comprehensive review of recently published articles, utilizing keywords such as "macrophage polarization" and "traditional Chinese medicines" in combination with "inflammation," as well as "macrophage polarization" and "inflammation" in conjunction with "natural products," and similar combinations, to search within PubMed and Google Scholar databases.

RESULTS

A total of 113 kinds of TCMs (including 62 components of TCMs, 27 TCMs as well as various types of extracts of TCMs and 24 Chinese prescriptions) was reported to exert anti-inflammatory effects through the regulation of key pathways of macrophage polarization and metabolic reprogramming.

CONCLUSIONS

In this review, we have analyzed studies concerning the involvement of macrophage polarization and metabolic reprogramming in inflammation therapy. TCMs has great advantages in regulating macrophage polarization in treating inflammatory diseases due to its multi-pathway and multi-target pharmacological action. This review may contribute to facilitate the development of natural anti-inflammatory drugs based on reshaping macrophage polarization.

Novel insights into macrophage immunometabolism in nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH), an inflammatory subtype of nonalcoholic fatty liver disease (NAFLD), is characterized by liver steatosis, inflammation, hepatocellular injury and different degrees of fibrosis, and has been becoming the leading cause of liver-related morbidity and mortality worldwide. Unfortunately, the pathogenesis of NASH has not been completely clarified, and there are no approved therapeutic drugs. Recent accumulated evidences have revealed the involvement of macrophage in the regulation of host liver steatosis, inflammation and fibrosis, and different phenotypes of macrophages have different metabolic characteristics. Therefore, targeted regulation of macrophage immunometabolism may contribute to the treatment and prognosis of NASH. In this review, we summarized the current evidences of the role of macrophage immunometabolism in NASH, especially focused on the related function conversion, as well as the strategies to promote its polarization balance in the liver, and hold promise for macrophage immunometabolism-targeted therapies in the treatment of NASH.

CSF1R inhibition reprograms tumor-associated macrophages to potentiate anti-PD-1 therapy efficacy against colorectal cancer

PD-1 blockade therapy has made great breakthroughs in treatment of multiple solid tumors. However, patients with microsatellite-stable (MSS) colorectal cancer (CRC) respond poorly to anti-PD-1 immunotherapy. Although CRC patients with microstatellite instability (MSI) or microsatellite instability-high (MSI-H) can benefit from PD-1 blockade therapy, there are still some problems such as tumor recurrence. Tumor-associated macrophages (TAMs), most abundant immune components in tumor microenvironment (TME), largely limit the therapeutic efficacy of anti-PD-1 against CRC. The CSF1/CSF1R pathway plays a key role in regulating macrophage polarization, and blocking CSF1R signaling transduction may be a potential strategy to effectively reprogram macrophages and remodel TME. Here, we found that increasing expression of CSF1R in macrophages predicted poor prognosis in CRC cohort. Furthermore, we discovered a novel potent CSF1R inhibitor, PXB17, which significantly reprogramed M2 macrophages to M1 phenotype. Mechanically, PXB17 significantly blocked activation of PI3K/AKT/mTORC1 signaling, resulting in inhibition of cholesterol biosynthesis. Results from 3D co-culture system suggested that PXB17-repolarized macrophages could induce infiltration of CD8+ T lymphocytes in tumors and improve the immunosuppressive microenvironment. In vivo, PXB17 significantly halted CRC growth, with a stronger effect than PLX3397. In particular, PXB17 potently enhanced therapeutic activity of PD-1 mAb in CT-26 (MSS) model and prevented tumor recurrence in MC-38 (MSI-H) model by promoting formation of long-term memory immunity. Our study opens a new avenue for CSF1R in tumor innate and adaptive anti-tumor immunomodulatory activity and suggests that PXB17 is a promising immunotherapy molecule for enhancing the efficacy of PD-1 mAb or reducing tumor recurrence of CRC.

Surfactant protein A promotes western diet-induced hepatic steatosis and fibrosis in mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) remains the most common cause of liver disease in the United States due to the increased incidence of metabolic dysfunction and obesity. Surfactant protein A (SPA) regulates macrophage function, strongly binds to lipids, and is implicated in renal and idiopathic pulmonary fibrosis (IPF). However, the role of SPA in lipid accumulation, inflammation, and hepatic fibrosis that characterize MASLD remains unknown. SPA deficient (SPA-/-) and age-matched wild-type (WT) control mice were fed a Western diet for 8 weeks to induce MASLD. Blood and liver samples were collected and used to analyze pathological features associated with MASLD. SPA expression was significantly upregulated in livers of mice with MASLD. SPA deficiency attenuated lipid accumulation along with downregulation of genes involved in fatty acid uptake and reduction of hepatic inflammation as evidenced by the diminished macrophage activation, decreased monocyte infiltration, and reduced production of inflammatory cytokines. Moreover, SPA-/- inhibited stellate cell activation, collagen deposit, and liver fibrosis. These results highlight the novel role of SPA in promoting fatty acid uptake into hepatocytes, causing excessive lipid accumulation, inflammation, and fibrosis implicated in the pathogenesis of MASLD.

Elucidating the changes in the heterogeneity and function of radiation-induced cardiac macrophages using single-cell RNA sequencing

Purpose

A mouse model of irradiation (IR)-induced heart injury was established to investigate the early changes in cardiac function after radiation and the role of cardiac macrophages in this process.

Methods

Cardiac function was evaluated by heart-to-tibia ratio, lung-to-heart ratio and echocardiography. Immunofluorescence staining and flow cytometry analysis were used to evaluate the changes of macrophages in the heart. Immune cells from heart tissues were sorted by magnetic beads for single-cell RNA sequencing, and the subsets of macrophages were identified and analyzed. Trajectory analysis was used to explore the differentiation relationship of each macrophage subset. The differentially expressed genes (DEGs) were compared, and the related enriched pathways were identified. Single-cell regulatory network inference and clustering (SCENIC) analysis was performed to identify the potential transcription factors (TFs) which participated in this process.

Results

Cardiac function temporarily decreased on Day 7 and returned to normal level on Day 35, accompanied by macrophages decreased and increased respectively. Then, we identified 7 clusters of macrophages by single-cell RNA sequencing and found two kinds of stage specific macrophages: senescence-associated macrophage (Cdkn1ahighC5ar1high) on Day 7 and interferon-associated macrophage (Ccr2highIsg15high) on Day 35. Moreover, we observed cardiac macrophages polarized over these two-time points based on M1/M2 and CCR2/major histocompatibility complex II (MHCII) expression. Finally, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses suggested that macrophages on Day 7 were characterized by an inflammatory senescent phenotype with enhanced chemotaxis and inflammatory factors, while macrophages on Day 35 showed enhanced phagocytosis with reduced inflammation, which was associated with interferon-related pathways. SCENIC analysis showed AP-1 family members were associated with IR-induced macrophages changes.

Conclusion

We are the first study to characterize the diversity, features, and evolution of macrophages during the early stages in an IR-induced cardiac injury animal model.

Roles of Chemokines in Intervertebral Disk Degeneration

PURPOSE OF REVIEW

Intervertebral disc degeneration is the primary etiology of low back pain and radicular pain. This review examines the roles of crucial chemokines in different stages of degenerative disc disease, along with interventions targeting chemokine function to mitigate disc degeneration.

RECENT FINDINGS

The release of chemokines from degenerated discs facilitates the infiltration and activation of immune cells, thereby intensifying the inflammatory cascade response. The migration of immune cells into the venous lumen is concomitant with the emergence of microvascular tissue and nerve fibers. Furthermore, the presence of neurogenic factors secreted by disc cells and immune cells stimulates the activation of pain-related cation channels in the dorsal root ganglion, potentially exacerbating discogenic and neurogenic pain and intensifying the degenerative cascade response mediated by chemokines. Gaining a deeper comprehension of the functions of chemokines and immune cells in these processes involving catabolism, angiogenesis, and injury detection could offer novel therapeutic avenues for managing symptomatic disc disease.

7-Ketocholesterol plays a key role in cholesterol-induced hepatitis via macrophage and neutrophil infiltration

This study sought to explore the role of 7-ketocholesterol (7-KC) in liver damage caused by high cholesterol intake and its potential pathological mechanism in mice. Our in vivo findings indicated that mice fed a high-cholesterol diet had elevated serum levels of 7-KC, accompanied by liver injury and inflammation, similar to human nonalcoholic steatohepatitis. Furthermore, the high-cholesterol diet induced neutrophil infiltration, which played a critical role in liver damage through myeloperoxidase (MPO) activity. Upon stimulation with 7-KC, macrophages exhibited increased expression of C-X-C motif chemokine ligand 1 (CXCL1) and CXCL2, as well as ATP-binding cassette transporter A1 (ABCA1) and ABCG1. Hepatocytes, on the other hand, exhibited increased expression of CXCL2 and ABCG1. The infiltration of neutrophils in the liver was primarily caused by CXCL1 and CXCL2, resulting in hepatocyte cell death due to elevated MPO activity. Our data also revealed that the activation of macrophages by 7-KC via ABCA1 or ABCG1 was not associated with lipid accumulation. Collectively, these findings suggest that high cholesterol-induced hepatitis in mice involves, at least partially, the recruitment of neutrophils to the liver by 7-KC-activated macrophages. This is mediated by increased expression of CXCL1 and CXCL2 through ABCA1 or ABCG1, which act as 7-KC efflux transporters. Additionally, hepatocytes contribute to this process by increased expression of CXCL2 through ABCG1. Therefore, our findings suggest that 7-KC may play a role in high cholesterol-induced hepatitis in mice by activating macrophages and hepatocytes, ultimately leading to neutrophil infiltration.

Key genes involved in nonalcoholic steatohepatitis improvement after bariatric surgery

Background

Nonalcoholic steatohepatitis (NASH) is the advanced stage of nonalcoholic fatty liver disease (NAFLD), one of the most prevalent chronic liver diseases. The effectiveness of bariatric surgery in treating NASH and preventing or even reversing liver fibrosis has been demonstrated in numerous clinical studies, but the underlying mechanisms and crucial variables remain unknown.

Methods

Using the GSE135251 dataset, we examined the gene expression levels of NASH and healthy livers. Then, the differentially expressed genes (DEGs) of patients with NASH, at baseline and one year after bariatric surgery, were identified in GSE83452. We overlapped the hub genes performed by protein-protein interaction (PPI) networks and DEGs with different expression trends in both datasets to obtain key genes. Genomic enrichment analysis (GSEA) and genomic variation analysis (GSVA) were performed to search for signaling pathways of key genes. Meanwhile, key molecules that regulate the key genes are found through the construction of the ceRNA network. NASH mice were induced by a high-fat diet (HFD) and underwent sleeve gastrectomy (SG). We then cross-linked the DEGs in clinical and animal samples using quantitative polymerase chain reaction (qPCR) and validated the key genes.

Results

Seven key genes (FASN, SCD, CD68, HMGCS1, SQLE, CXCL10, IGF1) with different expression trends in GSE135251 and GSE83452 were obtained with the top 30 hub genes selected by PPI. The expression of seven key genes in mice after SG was validated by qPCR. Combined with the qPCR results from NASH mice, the four genes FASN, SCD, HMGCS1, and CXCL10 are consistent with the biological analysis. The GSEA results showed that the 'cholesterol homeostasis' pathway was enriched in the FASN, SCD, HMGCS1, and SQLE high-expression groups. The high-expression groups of CD68 and CXCL10 were extremely enriched in inflammation-related pathways. The construction of the ceRNA network obtained microRNAs and ceRNAs that can regulate seven key genes expression.

Conclusion

In summary, this study contributes to our understanding of the mechanisms by which bariatric surgery improves NASH, and to the development of potential biomarkers for the treatment of NASH.