Targeting regulator of G protein signaling 1 in tumor-specific T cells enhances their trafficking to breast cancer.

Reduced infiltration of anti-tumor lymphocytes remains a major cause of tumor immune evasion and is correlated with poor cancer survival. Here, we found that upregulation of regulator of G protein signaling (RGS)1 in helper TH1 cells and cytotoxic T lymphocytes (CTLs) reduced their trafficking to and survival in tumors and was associated with shorter survival of patients with breast and lung cancer. RGS1 was upregulated by type II interferon (IFN)-signal transducer and activator of transcription (STAT)1 signaling and impaired trafficking of circulating T cells to tumors by inhibiting calcium influx and suppressing activation of the kinases ERK and AKT. RGS1 knockdown in adoptively transferred tumor-specific CTLs significantly increased their infiltration and survival in breast and lung tumor grafts and effectively inhibited tumor growth in vivo, which was further improved when combined with programmed death ligand (PD-L)1 checkpoint inhibition. Our findings reveal RGS1 is important for tumor immune evasion and suggest that targeting RGS1 may provide a new strategy for tumor immunotherapy.

Immune Checkpoint Inhibition Overcomes ADCP-Induced Immunosuppression by Macrophages.

Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) critically contribute to the efficacy of anti-tumor therapeutic antibodies. We report here an unexpected finding that macrophages after ADCP inhibit NK cell-mediated ADCC and T cell-mediated cytotoxicity in breast cancers and lymphomas. Mechanistically, AIM2 is recruited to the phagosomes by FcγR signaling following ADCP and activated by sensing the phagocytosed tumor DNAs through the disrupted phagosomal membrane, which subsequently upregulates PD-L1 and IDO and causes immunosuppression. Combined treatment with anti-HER2 antibody and inhibitors of PD-L1 and IDO enhances anti-tumor immunity and anti-HER2 therapeutic efficacy in mouse models. Furthermore, neoadjuvant trastuzumab therapy significantly upregulates PD-L1 and IDO in the tumor-associated macrophages (TAMs) of HER2+ breast cancer patients, correlating with poor trastuzumab response. Collectively, our findings unveil a deleterious role of ADCP macrophages in cancer immunosuppression and suggest that therapeutic antibody plus immune checkpoint blockade may provide synergistic effects in cancer treatment.

CD10+GPR77+ Cancer-Associated Fibroblasts Promote Cancer Formation and Chemoresistance by Sustaining Cancer Stemness.

Carcinoma-associated fibroblasts (CAFs) are abundant and heterogeneous stromal cells in tumor microenvironment that are critically involved in cancer progression. Here, we demonstrate that two cell-surface molecules, CD10 and GPR77, specifically define a CAF subset correlated with chemoresistance and poor survival in multiple cohorts of breast and lung cancer patients. CD10+GPR77+ CAFs promote tumor formation and chemoresistance by providing a survival niche for cancer stem cells (CSCs). Mechanistically, CD10+GPR77+ CAFs are driven by persistent NF-κB activation via p65 phosphorylation and acetylation, which is maintained by complement signaling via GPR77, a C5a receptor. Furthermore, CD10+GPR77+ CAFs promote successful engraftment of patient-derived xenografts (PDXs), and targeting these CAFs with a neutralizing anti-GPR77 antibody abolishes tumor formation and restores tumor chemosensitivity. Our study reveals a functional CAF subset that can be defined and isolated by specific cell-surface markers and suggests that targeting the CD10+GPR77+ CAF subset could be an effective therapeutic strategy against CSC-driven solid tumors.

NKILA lncRNA promotes tumor immune evasion by sensitizing T cells to activation-induced cell death.

Activation-induced cell death (AICD) of T lymphocytes can be exploited by cancers to escape immunological destruction. We demonstrated that tumor-specific cytotoxic T lymphocytes (CTLs) and type 1 helper T (TH1) cells, rather than type 2 helper T cells and regulatory T cells, were sensitive to AICD in breast and lung cancer microenvironments. NKILA, an NF-κB-interacting long noncoding RNA (lncRNA), regulates T cell sensitivity to AICD by inhibiting NF-κB activity. Mechanistically, calcium influx in stimulated T cells via T cell-receptor signaling activates calmodulin, thereby removing deacetylase from the NKILA promoter and enhancing STAT1-mediated transcription. Administering CTLs with NKILA knockdown effectively inhibited growth of breast cancer patient-derived xenografts in mice by increasing CTL infiltration. Clinically, NKILA overexpression in tumor-specific CTLs and TH1 cells correlated with their apoptosis and shorter patient survival. Our findings underscore the importance of lncRNAs in determining tumor-mediated T cell AICD and suggest that engineering lncRNAs in adoptively transferred T cells might provide a novel antitumor immunotherapy.

Tumour circular RNAs elicit anti-tumour immunity by encoding cryptic peptides.

Emerging data have shown that previously defined noncoding genomes might encode peptides that bind human leukocyte antigen (HLA) as cryptic antigens to stimulate adaptive immunity1,2. However, the significance and mechanisms of action of cryptic antigens in anti-tumour immunity remain unclear. Here mass spectrometry of the HLA class I (HLA-I) peptidome coupled with ribosome sequencing of human breast cancer samples identified HLA-I-binding cryptic antigenic peptides that were noncanonically translated by a tumour-specific circular RNA (circRNA): circFAM53B. The cryptic peptides efficiently primed naive CD4+ and CD8+ T cells in an antigen-specific manner and induced anti-tumour immunity. Clinically, the expression of circFAM53B and its encoded peptides was associated with substantial infiltration of antigen-specific CD8+ T cells and better survival in patients with breast cancer and patients with melanoma. Mechanistically, circFAM53B-encoded peptides had strong binding affinity to both HLA-I and HLA-II molecules. In vivo, administration of vaccines consisting of tumour-specific circRNA or its encoded peptides in mice bearing breast cancer tumours or melanoma induced enhanced infiltration of tumour-antigen-specific cytotoxic T cells, which led to effective tumour control. Overall, our findings reveal that noncanonical translation of circRNAs can drive efficient anti-tumour immunity, which suggests that vaccination exploiting tumour-specific circRNAs may serve as an immunotherapeutic strategy against malignant tumours.

LncRNA NRON promotes tumorigenesis by enhancing MDM2 activity toward tumor suppressor substrates.

The E3 ligase MDM2 promotes tumor growth and progression by inducing ubiquitin-mediated degradation of P53 and other tumor-suppressing proteins. Here, we identified an MDM2-interacting lncRNA NRON, which promotes tumor formation by suppressing both P53-dependent and independent pathways. NRON binds to MDM2 and MDMX (MDM4) via two different stem-loops, respectively, and induces their heterogenous dimerization, thereby enhancing the E3 ligase activity of MDM2 toward its tumor-suppressing substrates, including P53, RB1, and NFAT1. NRON knockdown dramatically inhibits tumor cell growth in vitro and in vivo. More importantly, NRON overexpression promotes oncogenic transformation by inducing anchorage-independent growth in vitro and facilitating tumor formation in immunocompromised mice. Clinically, NRON expression is significantly associated with poor clinical outcome in breast cancer patients. Together, our data uncover a pivotal role of lncRNA that induces malignant transformation of epithelial cells by inhibiting multiple tumor suppressor proteins.

DNA of neutrophil extracellular traps promotes cancer metastasis via CCDC25.

Neutrophil extracellular traps (NETs), which consist of chromatin DNA filaments coated with granule proteins, are released by neutrophils to trap microorganisms1-3. Recent studies have suggested that the DNA component of NETs (NET-DNA) is associated with cancer metastasis in mouse models4-6. However, the functional role and clinical importance of NET-DNA in metastasis in patients with cancer remain unclear. Here we show that NETs are abundant in the liver metastases of patients with breast and colon cancers, and that serum NETs can predict the occurrence of liver metastases in patients with early-stage breast cancer. NET-DNA acts as a chemotactic factor to attract cancer cells, rather than merely acting as a 'trap' for them; in several mouse models, NETs in the liver or lungs were found to attract cancer cells to form distant metastases. We identify the transmembrane protein CCDC25 as a NET-DNA receptor on cancer cells that senses extracellular DNA and subsequently activates the ILK-ß-parvin pathway to enhance cell motility. NET-mediated metastasis is abrogated in CCDC25-knockout cells. Clinically, we show that the expression of CCDC25 on primary cancer cells is closely associated with a poor prognosis for patients. Overall, we describe a transmembrane DNA receptor that mediates NET-dependent metastasis, and suggest that targeting CCDC25 could be an appealing therapeutic strategy for the prevention of cancer metastasis.

Identifying spatial domain by adapting transcriptomics with histology through contrastive learning.

Recent advances in spatial transcriptomics have enabled measurements of gene expression at cell/spot resolution meanwhile retaining both the spatial information and the histology images of the tissues. Accurately identifying the spatial domains of spots is a vital step for various downstream tasks in spatial transcriptomics analysis. To remove noises in gene expression, several methods have been developed to combine histopathological images for data analysis of spatial transcriptomics. However, these methods either use the image only for the spatial relations for spots, or individually learn the embeddings of the gene expression and image without fully coupling the information. Here, we propose a novel method ConGI to accurately exploit spatial domains by adapting gene expression with histopathological images through contrastive learning. Specifically, we designed three contrastive loss functions within and between two modalities (the gene expression and image data) to learn the common representations. The learned representations are then used to cluster the spatial domains on both tumor and normal spatial transcriptomics datasets. ConGI was shown to outperform existing methods for the spatial domain identification. In addition, the learned representations have also been shown powerful for various downstream tasks, including trajectory inference, clustering, and visualization.

Role of oxidative stress-induced ferroptosis in cancer therapy.

Ferroptosis is a distinct mode of cell death, distinguishing itself from typical apoptosis by its reliance on the accumulation of iron ions and lipid peroxides. Cells manifest an imbalance between oxidative stress and antioxidant equilibrium during certain pathological contexts, such as tumours, resulting in oxidative stress. Notably, recent investigations propose that heightened intracellular reactive oxygen species (ROS) due to oxidative stress can heighten cellular susceptibility to ferroptosis inducers or expedite the onset of ferroptosis. Consequently, comprehending role of ROS in the initiation of ferroptosis has significance in elucidating disorders related to oxidative stress. Moreover, an exhaustive exploration into the mechanism and control of ferroptosis might offer novel targets for addressing specific tumour types. Within this context, our review delves into recent fundamental pathways and the molecular foundation of ferroptosis. Four classical ferroptotic molecular pathways are well characterized, namely, glutathione peroxidase 4-centred molecular pathway, nuclear factor erythroid 2-related factor 2 molecular pathway, mitochondrial molecular pathway, and mTOR-dependent autophagy pathway. Furthermore, we seek to elucidate the regulatory contributions enacted by ROS. Additionally, we provide an overview of targeted medications targeting four molecular pathways implicated in ferroptosis and their potential clinical applications. Here, we review the role of ROS and oxidative stress in ferroptosis, and we discuss opportunities to use ferroptosis as a new strategy for cancer therapy and point out the current challenges persisting within the domain of ROS-regulated anticancer drug research and development.

Recent advances on neutrophil dysregulation in the pathogenesis of rheumatic diseases.

PURPOSE OF REVIEW: The exact pathogenic mechanisms of rheumatic diseases (RMD) remain largely unknown. Increasing evidence highlights a pathogenic role of neutrophil dysregulation in the development of RMD. RECENT FINDINGS: The purpose of this review is to present a current overview of recent advancements in understanding the role of neutrophil dysfunction in the development of RMD. Additionally, this review will discuss strategies for targeting pathways associated with neutrophil dysregulation as potential treatments for RMD. One specific aspect of neutrophil dysregulation, known as neutrophil extracellular traps (NETs), will be explored. NETs have been found to contribute to chronic pulmonary inflammation and fibrosis, as well as serve as DNA scaffolds for binding autoantigens, including both citrullinated and carbamylated autoantigens. Putative therapies, such as 6-gingerol or defibrotide, have demonstrated beneficial effects in the treatment of RMD by suppressing NETs formation. SUMMARY: Recent advances have significantly reinforced the crucial role of neutrophil dysregulation in the pathogenesis of RMD. A deeper understanding of the potential mechanisms underlying this pathogenic process would aid in the development of more precise and effective targeting strategies, thus ultimately improving the outcomes of RMD.

PMS2 amplification contributes brain metastasis from lung cancer.

BACKGROUND: Lung adenocarcinoma metastasizing to the brain results in a notable increase in patient mortality. The high incidence and its impact on survival presents a critical unmet need to develop an improved understanding of its mechanisms. METHODS: To identify genes that drive brain metastasis of tumor cells, we collected cerebrospinal fluid samples and paired plasma samples from 114 lung adenocarcinoma patients with brain metastasis and performed 168 panel-targeted gene sequencing. We examined the biological behavior of PMS2 (PMS1 Homolog 2)-amplified lung cancer cell lines through wound healing assays and migration assays. In vivo imaging techniques are used to detect fluorescent signals that colonize the mouse brain. RNA sequencing was used to compare differentially expressed genes between PMS2 amplification and wild-type lung cancer cell lines. RESULTS: We discovered that PMS2 amplification was a plausible candidate driver of brain metastasis. Via in vivo and in vitro assays, we validated that PMS2 amplified PC-9 and LLC lung cancer cells had strong migration and invasion capabilities. The functional pathway of PMS2 amplification of lung cancer cells is mainly enriched in thiamine, butanoate, glutathione metabolism. CONCLUSION: Tumor cells elevated expression of PMS2 possess the capacity to augment the metastatic potential of lung cancer and establish colonies within the brain through metabolism pathways.

Variation in innate immune responses to porcine epidemic diarrhea virus infection in piglets at different ages.

Porcine epidemic diarrhea virus (PEDV) poses a significant threat to pigs, with piglets under seven days old facing a mortality rate of up to 100 %. This study aimed to explore the maturation of the immune system in piglets across different age groups and their corresponding immune responses to PEDV infection. Real-time quantitative PCR was employed to assess the relative mRNA expression of inflammation-related factors in infected pigs compared to non-infected counterparts at varying ages. Additionally, flow cytometry was utilized to analyze the relative counts of CD4+ and CD8+ T cells, as well as CD21+ B cells, in peripheral blood, spleen, mesenteric lymph nodes, and Peyer's patches of piglets at different developmental stages. Our findings revealed a notable increase in IFN-α and IFN-γ, a decrease in TNF-α, and elevated expression of IL-1ß, IL-6, IL-10, and IL-17 following PEDV infection. Furthermore, the numbers of CD4+ and CD8+ T cells, along with CD21+ B cells, exhibited a gradual rise with the advancement of piglets' age. Overall, our study underscores the progressive enhancement of piglets' resistance to PEDV infection as their immune system matures over time.

In vitro and in vivo evaluation of thapsigargin as an antiviral agent against transmissible gastroenteritis virus.

Swine enteric coronaviruses (SeCoVs) pose a significant threat to the global pig industry, but no effective drugs are available for treatment. Previous research has demonstrated that thapsigargin (TG), an ER stress inducer, has broad-spectrum antiviral effects on human coronaviruses. In this study, we investigated the impact of TG on transmissible gastroenteritis virus (TGEV) infection using cell lines, porcine intestinal organoid models, and piglets. The results showed that TG effectively inhibited TGEV replication both in vitro and ex vivo. Furthermore, animal experiments demonstrated that oral administration of TG inhibited TGEV infection in neonatal piglets and relieved TGEV-associated tissue injury. Transcriptome analyses revealed that TG improved the expression of the ER-associated protein degradation (ERAD) component and influenced the biological processes related to secretion, nutrient responses, and epithelial cell differentiation in the intestinal epithelium. Collectively, these results suggest that TG is a potential novel oral antiviral drug for the clinical treatment of TGEV infection, even for infections caused by other SeCoVs.

Multi-Omics Integrated Analysis of the Protective Effect of EZH2 Inhibition in Mice with Renal Ischemia-Reperfusion Injury.

INTRODUCTION: Acute kidney injury (AKI) is a common clinical syndrome associated with high morbidity and mortality. Inhibition of the methyltransferase enhancer of zeste homolog 2 (EZH2) by its inhibitor 3-deazaneplanocin A (3-DZNeP) exerts renal benefits in acute renal ischemia-reperfusion injury (IRI). However, the underlying mechanisms are not completely known. This study aimed to elucidate the pathological mechanism of EZH2 in renal IRI by combination of multi-omics analysis and expression profiling in a public clinical cohort. METHODS: In this study, C57BL/6 J mice were used to establish the AKI model, which were treated with 3-DZNeP for 24 h. Kidney samples were collected for RNA-seq analysis, which was combined with publicly available EZH2 chromatin immunoprecipitation sequencing (ChIP-seq) data of mouse embryonic stem cell for a joint analysis to identify differentially expressed genes. Several selected differentially expressed genes were verified by quantitative PCR. Finally, single-nucleus sequencing data and expression profiling in public clinical datasets were used to confirm the negative correlation of the selected genes with EZH2 expression. RESULTS: 3-DZNeP treatment significantly improved renal pathology and function in IRI mice. Through RNA-seq analysis combined with EZH2 ChIP-seq database, 162 differentially expressed genes were found, which might be involved in EZH2-mediated pathology in IRI kidneys. Four differential expressed genes (Scd1, Cidea, Ghr, and Kl) related to lipid metabolism or cell growth were selected based on Gene Ontology and Kyoto Encyclopedia of Genes and Genome enrichment analysis, which were validated by quantitative PCR. Data from single-nucleus RNA sequencing revealed the negative correlation of these four genes with Ezh2 expression in different subpopulations of proximal tubular cells in IRI mice in a different pattern. Finally, the negative correlation of these four genes with EZH2 expression was confirmed in patients with AKI in two clinical datasets. CONCLUSIONS: Our study indicates that Scd1, Cidea, Ghr, and Kl are downstream genes regulated by EZH2 in AKI. Upregulation of EZH2 in AKI inhibits the expression of these four genes in a different population of proximal tubular cells to minimize normal physiological function and promote acute or chronic cell injuries following AKI.

Photoresponse of Solution-Synthesized Graphene Nanoribbon Heterojunctions on Diamond Indicating Phototunable Photodiode Polarity.

Graphene nanoribbon heterostructures and heterojunctions have attracted interest as next-generation molecular diodes with atomic precision. Their mass production via solution methods and prototypical device integration remains to be explored. Here, the bottom-up solution synthesis and characterization of liquid-phase-processable graphene nanoribbon heterostructures (GNRHs) are demonstrated. Joint photoresponsivity measurements and simulations provide evidence of the structurally defined heterostructure motif acting as a type-I heterojunction. Real-time, time-dependent density functional tight-binding simulations further reveal that the photocurrent polarity can be tuned at different excitation wavelengths. Our results introduce liquid-phase-processable, self-assembled heterojunctions for the development of nanoscale diode circuitry and adaptive hardware.

SUMOylation of Matrix Protein M1 and Filamentous Morphology Collectively Contribute to the Replication and Virulence of Highly Pathogenic H5N1 Avian Influenza Viruses in Mammals.

The matrix protein (M1) of influenza A virus plays an important role in replication, assembly, and budding. A previous study found that aspartic acid (D) at position 30 and alanine (A) at position 215 of M1 contribute to the high pathogenicity of H5N1 viruses in mice, and double mutations of D to asparagine (N) at position 30 (D30N) and A to threonine (T) at position 215 (A215T) in M1 dramatically attenuate H5N1 viruses in mice. However, the underlying mechanisms by which these M1 mutations attenuate the virulence of H5N1 viruses are unknown. Here, we found that the amino acid mutation A215T eliminates the SUMOylation of M1 by reducing its interaction with the host SUMO1 protein, significantly reducing the stability of M1, slowing the export of the M1-vRNP complex from the nucleus to the cytoplasm, and reducing viral replication in MDCK cells. We further found that the D30N mutation in M1 alters the shape of progeny viruses from filamentous to spherical virions. Our findings reveal an essential role for M1 215A SUMOylation and M1 30D-related filamentous morphology in the pathogenesis of avian influenza viruses, which could be targeted in novel antiviral drug designs. IMPORTANCE Identification of the pathogenic mechanism of highly pathogenic avian influenza viruses in mammals is helpful to develop novel anti-influenza virus strategies. Two amino acid mutations (D30N and A215T) in M1 were found to collectively attenuate H5N1 influenza viruses in mice, but the underlying mechanism remained unknown. This study found that the A215T mutation significantly decreases the SUMOylation of M1, which in turn attenuates the replication of H5N1 virus in mammalian cells. The D30N mutation in M1 was found to change the virion shape from filamentous to spherical. These findings are important for understanding the molecular mechanism of virulence of highly pathogenic avian influenza viruses in mammals.

Transmissible Gastroenteritis Virus Infection Promotes the Self-Renewal of Porcine Intestinal Stem Cells via Wnt/ß-Catenin Pathway.

Intestinal stem cells (ISCs) play an important role in tissue repair after injury. A recent report delineates the effect of transmissible gastroenteritis virus (TGEV) infection on the small intestine of recovered pigs. However, the mechanism behind the epithelium regeneration upon TGEV infection remains unclear. To address this, we established a TGEV infection model based on the porcine intestinal organoid monolayer. The results illustrated that the porcine intestinal organoid monolayer was susceptible to TGEV. In addition, the TGEV infection initiated the interferon and inflammatory responses following the loss of absorptive enterocytes and goblet cells. However, TGEV infection did not disturb epithelial integrity but induced the proliferation of ISCs. Furthermore, TGEV infection activated the Wnt/ß-catenin pathway by upregulating the accumulation and nuclear translocation of ß-catenin, as well as promoting the expression of Wnt target genes, such as C-myc, Cyclin D1, Mmp7, Lgr5, and Sox9, which were associated with the self-renewal of ISCs. Collectively, these data demonstrated that the TGEV infection activated the Wnt/ß-catenin pathway to promote the self-renewal of ISCs and resulted in intestinal epithelium regeneration. IMPORTANCE The intestinal epithelium is a physical barrier to enteric viruses and commensal bacteria. It plays an essential role in maintaining the balance between the host and intestinal microenvironment. In addition, intestinal stem cells (ISCs) are responsible for tissue repair after injury. Therefore, prompt self-renewal of intestinal epithelium will facilitate the rebuilding of the physical barrier and maintain gut health. In the manuscript, we found that the transmissible gastroenteritis virus (TGEV) infection did not disturb epithelial integrity but induced the proliferation of ISCs and facilitated epithelium regeneration. Detailed mechanism investigations revealed that the TGEV infection activated the Wnt/ß-catenin pathway to promote the self-renewal of ISCs and resulted in intestinal epithelium regeneration. These findings will contribute to understanding the mechanism of intestinal epithelial regeneration and reparation upon viral infection.

Lamina propria interleukin 17 A aggravates natural killer T-cell activation in autoimmune hepatitis.

Autoimmune hepatitis is an interface hepatitis characterized by the progressive destruction of the liver parenchyma, the cause of which is still obscure. Interleukin (IL)-17A is a major driver of autoimmunity, which can be produced by innate immune cells against several intracellular pathogens. Here, we investigated the involvement of IL-17A in a mice model of immune-mediated hepatitis with the intestine exposed to Salmonella typhimurium. Our results showed more severe Concanavalin (Con) A-induced liver injury and gut microbiome dysbiosis when the mice were treated with a gavage of S. typhimurium. Then, the natural killer (NK) T cells were overactivated by the accumulated IL-17A in the liver in the Con A and S. typhimurium administration group. IL-17A could activate NKT cells by inducing CD178 expression via IL-4/STAT6 signaling. Furthermore, via the portal tract, the laminae propria mucosal-associated invariant T (MAIT)-cell-derived IL-17A could be the original driver of NKT cell overactivation in intragastric administration of S. typhimurium and Con A injection. In IL-17A-deficient mice, Con A-induced liver injury and NKT cell activation were alleviated. However, when AAV-sh-mIL-17a was used to specifically knock down IL-17A in liver, it seemed that hepatic IL-17a knock down did not significantly influence the liver injury. Our results suggested that, under Con A-induction, laminae propria MAIT-derived IL-17A activated hepatic NKT, and this axis could be a therapeutic target in autoimmune liver disease.

Celastrol pretreatment attenuates concanavalin A-induced hepatitis in mice by suppressing interleukin-6/STAT3-interleukin-17 signaling.

BACKGROUND AND AIM: Celastrol is extracted from Tripterygium wilfordii Hook F. It has been reported to have protective effects against various liver diseases and immune regulation of autoimmune diseases. However, little is known about whether celastrol protects against immune-mediated hepatitis. This study aimed to investigate the effect of celastrol on liver injury induced by concanavalin A (ConA) and the potential mechanisms. METHODS: Intravenous administration of ConA was applied to induce acute liver injury in mice with or without pretreatment of celastrol. The effects of celastrol on ConA-induced liver injury were further demonstrated by biochemical and histopathological assessments, immunoblotting, and flow cytometry analysis. RESULTS: Both biochemical and histopathological observations showed that pretreatment of celastrol significantly ameliorated liver injury induced by ConA. Moreover, the hepatocyte apoptosis and inflammatory responses induced by ConA were also improved in celastrol-pretreated mice. Further studies revealed that these improvements were characterized as the celastrol-mediated suppression of total interleukin (IL)-17 from liver mononuclear cells in ConA-treated mice. Flow cytometry analysis suggested that celastrol specifically decreased IL-17 production by CD4+ T cells but not by CD8+ T cells. Fundamentally, pretreatment with celastrol inhibited both the IL-6 produced by F4/80+ macrophages and the IL-6 receptor on Th17 cells in the liver, which further led to the downregulated activation of STAT3, thus accounting for blocked Th17 signaling. CONCLUSIONS: Celastrol may exhibit immune regulatory effects by regulating IL-6/STAT3-IL-17 signaling in ConA-induced hepatitis, which suggested new potentials for celastrol to be applied in treating immune-mediated liver diseases.

Osteopontin May Improve Postinjury Muscle Repair Via Matrix Metalloproteinases And tgf-ß Activation in Regular Exercise.

Skeletal muscle injuries are commonly observed during sports and trauma. Regular exercise promotes muscle repair; however, the underlying mechanisms require further investigation. In addition to exercise, osteopontin (OPN) contributes to skeletal muscle regeneration and fibrosis following injury. However, whether and how OPN affects matrix proteins to promote post-injury muscle repair remains uncertain. We recruited regular exercise (RE) and sedentary control (SC) groups to determine plasma OPN levels. Additionally, we developed a murine model of muscle contusion injury and compared the extent of damage, inflammatory state, and regeneration-related proteins in OPN knockout (OPN KO) and wild-type (WT) mice. Our results show that regular exercise induced the increase of OPN, matrix metalloproteinases (MMPs), and transforming growth factor-ß (TGF-ß) expression in plasma. Injured muscle fibers were repaired more slowly in OPN-KO mice than in WT mice. The expression levels of genes and proteins related to muscle regeneration were lower in OPN-KO mice after injury. OPN also promotes fibroblast proliferation, differentiation, and migration. Additionally, OPN upregulates MMP expression by activating TGF-ß, which promotes muscle repair. OPN can improve post-injury muscle repair by activating MMPs and TGF-ß pathways. It is upregulated by regular exercise. Our study provides a potential target for the treatment of muscle injuries and explains why regular physical exercise is beneficial for muscle repair.