Napabucasin deactivates STAT3 and promotes mitoxantrone-mediated cGAS-STING activation for hepatocellular carcinoma chemo-immunotherapy.

The immune resistance of tumor microenvironment (TME) causes immune checkpoint blockade therapy inefficient to hepatocellular carcinoma (HCC). Emerging strategies of using chemotherapy regimens to reverse the immune resistance provide the promise for promoting the efficiency of immune checkpoint inhibitors. The induction of cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) in tumor cells evokes the adaptive immunity and remodels the immunosuppressive TME. In this study, we report that mitoxantrone (MIT, a chemotherapeutic drug) activates the cGAS-STING signaling pathway of HCC cells. We provide an approach to augment the efficacy of MIT using a signal transducer and activator of transcription 3 (STAT3) inhibitor called napabucasin (NAP). We prepare an aminoethyl anisamide (AEAA)-targeted polyethylene glycol (PEG)-modified poly (lactic-co-glycolic acid) (PLGA)-based nanocarrier for co-delivery of MIT and NAP. The resultant co-nanoformulation can elicit the cGAS-STING-based immune responses to reshape the immunoresistant TME in the mice orthotopically grafted with HCC. Consequently, the resultant co-nanoformulation can promote anti-PD-1 antibody for suppressing HCC development, generating long-term survival, and inhibiting tumor recurrence. This study reveals the potential of MIT to activate the cGAS-STING signaling pathway, and confirms the feasibility of nano co-delivery for MIT and NAP on achieving HCC chemo-immunotherapy.

In vitro biomaterial priming of human mesenchymal stromal/stem cells : implication of the Src/JAK/STAT3 pathway in vasculogenic mimicry.

Mesenchymal stromal/stem cells (MSC) play a crucial role in promoting neovascularization, which is essential for wound healing. They are commonly utilized as an autologous source of progenitor cells in various stem cell-based therapies. However, incomplete MSC differentiation towards a vascular endothelial cell phenotype questions their involvement in an alternative process to angiogenesis, namely vasculogenic mimicry (VM), and the signal transducing events that regulate their in vitro priming into capillary-like structures. Here, human MSC were primed on top of Cultrex matrix to recapitulate an in vitro phenotype of VM. Total RNA was extracted, and differential gene expression assessed through RNA-Seq analysis and RT-qPCR. Transient gene silencing was achieved using specific siRNA. AG490, Tofacitinib, and PP2 pharmacological effects on VM structures were analyzed using the Wimasis software. In vitro VM occurred within 4 h and was prevented by the JAK/STAT3 inhibitors AG490 and Tofacitinib, as well as by the Src inhibitor PP2. RNA-Seq highlighted STAT3 as a signaling hub contributing to VM when transcripts from capillary-like structures were compared to those from cell monolayers. Concomitant increases in IL6, IL1b, CSF1, CSF2, STAT3, FOXC2, RPSA, FN1, and SNAI1 transcript levels suggest the acquisition of a combined angiogenic, inflammatory and epithelial-to-mesenchymal transition phenotype in VM cultures. Increases in STAT3, FOXC2, RPSA, Fibronectin, and Snail protein expression were confirmed during VM. STAT3 and RPSA gene silencing abrogated in vitro VM. In conclusion, in vitro priming of MSC into VM structures requires Src/JAK/STAT3 signaling. This molecular evidence indicates that a clinically viable MSC-mediated pseudo-vasculature process could temporarily support grafts through VM, allowing time for the host vasculature to infiltrate and remodel the injured tissues.

Water-soluble garlic polysaccharide (WSGP) improves ulcerative volitis by modulating the intestinal barrier and intestinal flora metabolites.

WSGP has demonstrated significant potential for various bioactive effects. However, limited research has explored their anti-ulcerative colitis (UC) effects and mechanism on the colonic system and gut microbial metabolites. We evaluated the ameliorative effects of WSGP on the UC mice model. Using H&E to assess histological injury of colon morphology, AB-PAS staining to detect mucin secretion from goblet cells and the mucous layer, IF to evaluate the expression of intercellular tight junction proteins, ELISA to measure inflammatory factors, WB analysis to measure protein expression of inflammatory signaling pathways, RT-qPCR to quantify gene transcription of inflammatory factors, and LC-MS to analyze metabolites in mouse cecum contents. WSGP supplementation increased food intake, body weight, and colon length while reducing disease activity and histological scores in colitis-afflicted mice. WSGP mitigated colonic tissue damage and restored intestinal barrier integrity by suppressing NF-κB/STAT3 signaling, thereby decreasing gene transcription, protein expression of proinflammatory factors, and nitric oxide production. Additionally, WSGP improved UC by altering the variety of intestinal microbial metabolites. This study demonstrates that WSGP supplementation attenuates UC mice by suppressing the NF-κB/STAT3 signaling pathway, enhancing mucosal barrier function, reducing pro-inflammatory cytokines, and modulating gut microbial metabolites.

pSTAT3 activation of Foxl2 initiates the female pathway underlying temperature-dependent sex determination.

Ovarian development was traditionally recognized as a "default" sexual outcome and therefore received much less scientific attention than testis development. In turtles with temperature-dependent sex determination (TSD), how the female pathway is initiated to induce ovary development remains unknown. In this study, we have found that phosphorylation of the signal transducer and activator of transcription 3 (pSTAT3) and Foxl2 exhibit temperature-dependent sexually dimorphic patterns and tempo-spatial coexpression in early embryos of the red-eared slider turtle (Trachemys scripta elegans). Inhibition of pSTAT3 at a female-producing temperature of 31 °C induces 64.7% female-to-male sex reversal, whereas activation of pSTAT3 at a male-producing temperature of 26 °C triggers 75.6% male-to-female sex reversal. In addition, pSTAT3 directly binds to the locus of the female sex-determining gene Foxl2 and promotes Foxl2 transcription. Overexpression or knockdown of Foxl2 can rescue the sex reversal induced by inhibition or activation of pSTAT3. This study has established a direct genetic link between warm temperature-induced STAT3 phosphorylation and female pathway initiation in a TSD system, highlighting the critical role of pSTAT3 in the cross talk between female and male pathways.

Microglia mediate memory dysfunction via excitatory synaptic elimination in a fracture surgery mouse model.

Cognitive impairment is a common issue among human patients undergoing surgery, yet the neural mechanism causing this impairment remains unidentified. Surgical procedures often lead to glial cell activation and neuronal hypoexcitability, both of which are known to contribute to postoperative cognitive dysfunction (POCD). However, the role of neuron-glia crosstalk in the pathology of POCD is still unclear. Through integrated transcriptomics and proteomics analyses, we found that the complement cascades and microglial phagocytotic signaling pathways are activated in a mouse model of POCD. Following surgery, there is a significant increase in the presence of complement C3, but not C1q, in conjunction with presynaptic elements. This triggers a reduction in excitatory synapses, a decline in excitatory synaptic transmission, and subsequent memory deficits in the mouse model. By genetically knockout out C3ar1 or inhibiting p-STAT3 signaling, we successfully prevented neuronal hypoexcitability and alleviated cognitive impairment in the mouse model. Therefore, targeting the C3aR and downstream p-STAT3 signaling pathways could serve as potential therapeutic approaches for mitigating POCD.

The functional role of m6A demethylase ALKBH5 in cardiomyocyte hypertrophy.

Cardiomyocyte hypertrophy is a major outcome of pathological cardiac hypertrophy. The m6A demethylase ALKBH5 is reported to be associated with cardiovascular diseases, whereas the functional role of ALKBH5 in cardiomyocyte hypertrophy remains confused. We engineered Alkbh5 siRNA (siAlkbh5) and Alkbh5 overexpressing plasmid (Alkbh5 OE) to transfect cardiomyocytes. Subsequently, RNA immunoprecipitation (RIP)-qPCR, MeRIP-qPCR analysis and the dual-luciferase reporter assays were applied to elucidate the regulatory mechanism of ALKBH5 on cardiomyocyte hypertrophy. Our study identified ALKBH5 as a new contributor of cardiomyocyte hypertrophy. ALKBH5 showed upregulation in both phenylephrine (PE)-induced cardiomyocyte hypertrophic responses in vitro and transverse aortic constriction (TAC)/high fat diet (HFD)-induced pathological cardiac hypertrophy in vivo. Knockdown or overexpression of ALKBH5 regulated the occurrence of hypertrophic responses, including the increased cardiomyocyte surface areas and elevation of the hypertrophic marker levels, such as brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP). Mechanically, we indicated that ALKBH5 activated JAK2/STAT3 signaling pathway and mediated m6A demethylation on Stat3 mRNA, but not Jak2 mRNA, resulting in the phosphorylation and nuclear translocation of STAT3, which enhances the transcription of hypertrophic genes (e.g., Nppa) and ultimately leads to the emergence of cardiomyocytes hypertrophic growth. Our work highlights the functional role of ALKBH5 in regulating the onset of cardiomyocyte hypertrophy and provides a potential target for hypertrophic heart diseases prevention and treatment. ALKBH5 activated JAK2/STAT3 signaling pathway and mediated m6A demethylation on Stat3 mRNA, but not Jak2 mRNA, resulting in the phosphorylation and nuclear translocation of STAT3, which enhances the transcription of hypertrophic genes (e.g., Nppa) and ultimately leads to the emergence of cardiomyocytes hypertrophic growth.

Baicalin target protein, Annexin A2, is a target of new antitumor drugs.

Baicalin is a flavonoid extracted from Scutellaria baicalensis Georgi. As it has significant antitumor and apoptosis-inducing effects, baicalin may be useful as a lead compound in new antitumor drug development. However, as the pharmacological actions of baicalin have yet to be elucidated, we isolated its target protein, which was successfully identified as Annexin A2. Annexin A2 forms a heterotetramer with S100A10 protein, which plays an important role in the plasminogen activator system. The heterotetramer bound to tissue plasminogen activator (tPA) activates the conversion of plasminogen to plasmin and promotes the expression of STAT-3 and NF-κB, which are target genes involved in the development of cancer. Moreover, NF-κB and STAT-3 induce the expression of cell inhibitors of apoptotic proteins and inhibit apoptosis. To examine whether these antitumor and apoptosis-inducing effects of baicalin are mediated by Annexin A2, we prepared Annexin A2 knockdown HepG2 cells. We compared mRNA expression by RT-qPCR and apoptosis by caspase-3 activity assays in Annexin A2 knockdown HepG2 cells. The results showed that the antitumor and apoptosis-inducing effects of baicalin are mediated by Annexin A2. The results of this study suggest that agents capable of inhibiting Annexin A2 may be useful candidates for the development of novel antitumor agents.

Characterization of the angiomodulatory effects of Interleukin 11 cis- and trans-signaling in the retina.

BACKGROUND: The IL-6 cytokine family, with its crucial and pleiotropic intracellular signaling pathway STAT3, is a promising target for treating vasoproliferative retinal diseases. Previous research has shown that IL-6 cis-signaling (via membrane-bound receptors) and trans-signaling (via soluble receptors) can have distinct effects on target cells, leading to their application in various disease treatments. While IL-6 has been extensively studied, less is known about the angiogenic effects of IL-11, another member of the IL-6 family, in the retina. Therefore, the aim of this study was to characterize the effects of IL-11 on retinal angiogenesis. MAIN TEXT: In vitreous samples from proliferative diabetic retinopathy (PDR) patients, elevated levels of IL-11Rα, but not IL-11, were detected. In vitro studies using vascular endothelial cells revealed distinct effects of cis- and trans-signaling: cis-signaling (IL-11 alone) had antiangiogenic effects, while trans-signaling (IL-11 + sIL-11Rα) had proangiogenic and pro-migratory effects. These differences can be attributed to their individual signaling responses and associated transcriptomic changes. Notably, no differences in cis- and trans-signaling were detected in primary mouse Müller cell cultures. STAT3 and STAT1 siRNA knockdown experiments revealed opposing effects on IL-11 signaling, with STAT3 functioning as an antiproliferative and proapoptotic player while STAT1 acts in opposition to STAT3. In vivo, both IL-11 and IL-11 + sIL-11Rα led to a reduction in retinal neovascularization. Immunohistochemical staining revealed Müller cell activation in response to treatment, suggesting that IL-11 affects multiple retinal cell types in vivo beyond vascular endothelial cells. CONCLUSIONS: Cis- and trans-signaling by IL-11 have contrasting angiomodulatory effects on endothelial cells in vitro. In vivo, cis- and trans-signaling also influence Müller cells, ultimately determining the overall angiomodulatory impact on the retina, highlighting the intricate interplay between vascular and glial cells in the retina.

[Therapeutic mechanism of Cynanchum wilfordii for ulcerative colitis: an analysis using UPLC-QE-MS, network pharmacology and metabolomics].

OBJECTIVE: To explore the targets and pathways of Cynanchum wilfordii for treatment of ulcerative colitis (UC). METHODS: UPLC-QE-MS was used to identify the components of Cynanchum wilfordii ethanol extract, and their targets were screened using public databases for construction of the core protein-protein interaction (PPI) network and GO and KEGG enrichment analyses. Forty male C57 mice were randomized into normal control group, model group, mesalazine group and Cynanchum wilfordii group (n=10), and in the latter 3 groups, mouse UC models were established by treatment with 2.5% DSS and the latter 2 groups drug interventions by gavage. The therapeutic effect was evaluated by recording body weight changes and DAI score. Pathological changes of the colon tissue were observed with HE and AB-PAS staining, and JAK2 and STAT3 protein expressions were detected with Western blotting. The metabolites and metabolic pathways were identified by metabonomics analysis. RESULTS: We identified 240 chemical components in Cynanchum wilfordii alcoholic extracts, including 19 steroids. A total of 177 Cynanchum wilfordii targets, 5406 UC genes, and 117 intersection genes were obtained. JAK2 and STAT3 were the core targets and significantly enriched in lipid and atherosclerosis pathways. Cynanchum wilfordii treatment significantly increased the body weight and decreased DAI score of UC mice (P < 0.05), alleviated intestinal pathologies, and decreased JAK2 and STAT3 protein expressions in the colon tissues. Most of the 83 intersecting differential metabolites between the control, model and Cynanchum wilfordii groups were identified as glycerophospholipids, arachidonic acid, and amino acids involving glycerophospholipid metabolism and other pathways. Correlation analysis suggested that the core targets of Cynanchum wilfordii for UC participated in regulation of the metabolites. CONCLUSION: Cynanchum wilfordii alleviates lipid and amino acid metabolism disorders to lessen UC in mice by regulating the core targets including JAK2 and STAT3 and the levels of endogenous metabolites.

Mineralocorticoid Receptor Blocker Prevents Mineralocorticoid Receptor-Mediated Inflammation by Modulating Transcriptional Activity of Mineralocorticoid Receptor-p65-Signal Transducer and Activator of Transcription 3 Complex.

BACKGROUND: Mineralocorticoid receptor (MR) induces cardiac inflammation cooperatively with nuclear factor-κB and signal transducer and activator of transcription 3 (STAT3); MR blockers exert anti-inflammatory effects. However, the underlying mechanism remains unclear. We investigated the anti-inflammatory effect of esaxerenone, a novel MR blocker, in experimental myocardial infarction (MI) and its underlying mechanisms. METHODS AND RESULTS: Male C57BL/6J mice subjected to ligation of the left anterior descending artery were randomly assigned to either the vehicle or esaxerenone group. Esaxerenone was provided with a regular chow diet. The mice were euthanized at either 4 or 15 days after MI. Cardiac function, fibrosis, and inflammation were evaluated. Esaxerenone significantly improved cardiac function and attenuated cardiac fibrosis at 15 days after MI independently of its antihypertensive effect. Inflammatory cell infiltration, inflammatory-related gene expression, and elevated serum interleukin-6 levels at 4 days after MI were significantly attenuated by esaxerenone. In vitro experiments using mouse macrophage-like cell line RAW264.7 cells demonstrated that esaxerenone- and spironolactone-attenuated lipopolysaccharide-induced interleukin-6 expression without altering the posttranslational modification and nuclear translocation of p65 and STAT3. Immunoprecipitation assays revealed that MR interacted with both p65 and STAT3 and enhanced the p65-STAT3 interaction, leading to a subsequent increase in interleukin-6 promoter activity, which was reversed by esaxerenone. CONCLUSIONS: Esaxerenone ameliorated postinfarct remodeling in experimental MI through its anti-inflammatory properties exerted by modulating the transcriptional activity of the MR-p65-STAT3 complex. These results suggest that the MR-p65-STAT3 complex can be a novel therapeutic target for treating MI.

JAK inhibitors to treat STAT3 gain-of-function: a single-center report and literature review.

Objective: The signal transducer and activator of transcription 3 (STAT3) gain-of-function (GOF) syndrome (STAT3-GOF) is an inborn error of immunity (IEI) characterized by diverse manifestations of immune dysregulation that necessitate systemic immunomodulatory treatment. The blockade of the interleukin-6 receptor and/or the inhibition of the Janus kinases has been commonly employed to treat diverse STAT3-GOF-associated manifestations. However, evidence on long-term treatment outcome, especially in the case of adult patients, is scarce. Methods: Clinical data, including laboratory findings and medical imaging, were collected from all seven patients, diagnosed with STAT3-GOF, who have been treated at the Hannover University School, focusing on those who received a Janus kinase (JAK) inhibitor (JAKi). Previously published cases of STAT3-GOF patients who received a JAKi were evaluated, focusing on reported treatment efficacy with respect to diverse STAT3-GOF-associated manifestations of immune dysregulation and safety. Results: Five out of seven patients diagnosed with STAT3-GOF were treated with a JAKi, each for a different indication. Including these patients, outcomes of JAKi treatment have been reported for a total of 41 patients. Treatment with a JAKi led to improvement of diverse autoimmune, inflammatory, or lymphoproliferative manifestations of STAT3-GOF and a therapeutic benefit could be documented for all except two patients. Considering all reported manifestations of immune dysregulation in each patient, complete remission was achieved in 10/41 (24.4%) treated patients. Conclusions: JAKi treatment improved diverse manifestations of immune dysregulation in the majority of STAT3-GOF patients, representing a promising therapeutic approach. Long-term follow-up data are needed to evaluate possible risks of prolonged treatment with a JAKi.

The Mechanism of Leptin Resistance in Obesity and Therapeutic Perspective.

Leptin resistance is induced via leptin signaling blockade by chronic overstimulation of the leptin receptor and intracellular signaling defect or increased hypothalamic inflammation and suppressor of cytokine signaling (SOCS)-3 expression. High-fat diet triggers leptin resistance induced by at least two independent causes: first, the limited ability of peripheral leptin to activate hypothalamic signaling transducers and activators of transcription (STAT) signaling and secondly a signaling defect in leptin-responsive hypothalamic neurons. Central leptin resistance is dependent on decreased leptin transport efficiency across the blood brain barrier (BBB) rather than hypothalamic leptin insensitivity. Since the hypothalamic phosphorylated STAT3 (pSTAT3) represents a sensitive and specific readout of leptin receptor-B signaling, the assessment of pSTAT3 levels is the gold standard. Hypertriglyceridemia is one of important factors to inhibit the transport of leptin across BBB in obesity. Mismatch between high leptin and the amount of leptin receptor expression in obesity triggers brain leptin resistance via increasing hypothalamic inflammation and SOCS-3 expression. Therapeutic strategies that regulate the passage of leptin to the brain include the development of modifications in the structure of leptin analogues as well as the synthesis of new leptin receptor agonists with increased BBB permeability. In the hyperleptinemic state, polyethylene glycol (PEG)-modified leptin is unable to pass through the BBB. Peripheral histone deacetylase (HDAC) 6 inhibitor, tubastatin, and metformin increase central leptin sensitization. While add-on therapy with anagliptin, metformin and miglitol reduce leptin concentrations, the use of long-acting leptin analogs, and exendin-4 lead to the recovery of leptin sensitivity. Contouring surgery with fat removal, and bariatric surgery independently of the type of surgery performed provide significant improvement in leptin concentrations. Although approaches to correcting leptin resistance have shown some success, no clinically effective application has been developed to date. Due to the impairment of central and peripheral leptin signaling, as well as the extensive integration of leptin-sensitive metabolic pathways with other neurons, the effectiveness of methods used to eliminate leptin resistance is extremely limited.

Mesenchymal stem cell-derived extracellular vesicles targeting irradiated intestine exert therapeutic effects.

Background: Radiation-induced intestinal injuries are common in patients with pelvic or abdominal cancer. However, these injuries are currently not managed effectively. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been extensively used in regenerative medicine. However, the results of MSC-EVs in the repair of radiation-induced intestinal damage have been unsatisfactory. We here investigated the nanotherapeutic functions of MSC-EVs in radiation-induced intestinal injury. Methods: We visualized the biodistribution and trend of MSC-EVs through in vivo imaging. A radiation-induced intestinal injury model was constructed, and the therapeutic effect of MSC-EVs was explored through in vivo and in vitro experiments. Immunofluorescence and qRT-PCR assays were conducted to explore the underlying mechanisms. Results: MSC-EVs exhibited a dose-dependent tendency to target radiation-injured intestines while providing spatiotemporal information for the early diagnosis of the injury by quantifying the amount of MSC-EVs in the injured intestines through molecular imaging. Meanwhile, MSC-EVs displayed superior nanotherapeutic functions by alleviating apoptosis, improving angiogenesis, and ameliorating the intestinal inflammatory environment. Moreover, MSC-EVs-derived miRNA-455-5p negatively regulated SOCS3 expression, and the activated downstream Stat3 signaling pathway was involved in the therapeutic efficacy of MSC-EVs in radiation-induced intestinal injuries. Conclusion: MSC-EVs can dose-dependently target radiation-injured intestinal tissues, allow a spatiotemporal diagnosis in different degrees of damage to help guide personalized therapy, offer data for designing EV-based theranostic strategies for promoting recovery from radiation-induced intestinal injury, and provide cell-free treatment for radiation therapy.

SPRR1B+ keratinocytes prime oral mucosa for rapid wound healing via STAT3 activation.

Oral mucosal wounds exhibit accelerated healing with reduced scarring compared to cutaneous wounds, representing an optimal wound healing paradigm. However, the specific cellular subtypes orchestrating the efficient healing of mucosal tissues remain elusive. Through a comprehensive analysis integrating bulk-mRNA and single-cell sequencing data during the wound healing process in oral mucosa and skin, we have delineated a distinct set of genes markedly upregulated during tissue repair. This collection of wound healing-associated genesets was highly enriched in a specific keratinocyte subpopulation identified as STAT3-activated SPRR1B+ keratinocytes. Notably, despite the inherent rapidity of oral mucosal healing, the induction of SPRR1B+ keratinocytes is evident in both skin and mucosal wound healing processes in murine model. Intriguingly, these wound healing-promoting SPRR1B+ keratinocytes, which are induced via STAT3 activation, inherently abundant in unwounded normal mucosa but absent in normal skin. SPRR1B knockdown significantly inhibits mucosal keratinocyte migration, a critical attribute for effective wound healing. In summary, through analysis of human oral and skin wound healing processes at single-cell resolution, coupled with validation in murine model, suggests STAT3-activated SPRR1B+ keratinocytes are associated with the rapid mucosal repair process. This discovery underscores the potential application of SPRR1B+ keratinocytes in the therapeutic management of chronic or non-healing wounds.

Demethylzeylasteral ameliorates podocyte damage in murine lupus by inhibiting inflammation and enhancing autophagy.

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multiorgan and tissue involvement. Lupus nephritis (LN), an inflammatory condition of the kidneys associated with SLE, represents a significant cause of morbidity and mortality in SLE patients. Current immunosuppressive therapies for LN have limited efficacy and can lead to significant side effects. Demethylzeylasteral (DML) has shown promise in the treatment of LN, but its precise mechanism of action remains unclear. PURPOSE: To assess the therapeutic effects and potential molecular mechanisms of DML in LN METHODS: The study evaluated the renal protective effects of DML in MRL/lpr mice through assessments of immune complex levels, renal function, and pathological changes. Network pharmacology and transcriptomics approaches were used to elucidate the underlying mechanisms. Molecular docking, biacore assay, monoclonal antibody blocking experiments, and in vitro studies were conducted to verify the mechanisms of action. RESULTS: DML treatment reduced levels of anti-Sm and anti-dsDNA IgG antibodies, as well as serum creatinine and blood urea nitrogen levels. DML also mitigated glomerular damage and fibrosis. Mechanistically, DML alleviated podocyte damage by suppressing inflammation and enhancing autophagy through inhibition of the IL-17A/JAK2-STAT3 pathways. Additionally, DML exhibited high binding affinity with IL17A, JAK2, and STAT3. CONCLUSION: These findings provide strong evidence for the beneficial effects of DML in LN, suggesting its potential as a novel therapeutic strategy for improving renal function in autoimmune kidney diseases.

Innate immunity gene Nod2 protects mice from orthotopic breast cancer.

BACKGROUND: Nod2 is involved in innate immune responses to bacteria, regulation of metabolism, and sensitivity to cancer. A Nod2 polymorphism is associated with breast cancer, but the role of Nod2 in the development and progression of breast cancer is unknown. METHODS: Here, we tested the hypothesis that Nod2 protects mice from breast cancer using the 4T1 orthotopic model of mammary tumorigenesis. WT and Nod2-/- mice were injected with 4T1 mammary carcinoma cells and the development of tumors was monitored. A detailed analysis of the tumor transcriptome was performed and genes that were differentially expressed and pathways that were predicted to be altered between WT and Nod2-/- mice were identified. The activation of key signaling molecules involved in metabolism and development of cancer was studied. RESULTS: Our data demonstrate that Nod2-/- mice had a higher incidence and larger tumors than WT mice. Nod2-/- mice had increased expression of genes that promote DNA replication and cell division, and decreased expression of genes required for lipolysis, lipogenesis, and steroid biosynthesis compared with WT mice. Nod2-/- mice also had lower expression of genes required for adipogenesis and reduced levels of lipids compared with WT mice. The tumors in Nod2-/- mice had decreased expression of genes associated with PPARα/γ signaling, increased activation of STAT3, decreased activation of STAT5, and no change in the activation of ERK compared with WT mice. CONCLUSIONS: We conclude that Nod2 protects mice from the 4T1 orthotopic breast tumor, and that tumors in Nod2-/- mice are predicted to have increased DNA replication and cell proliferation and decreased lipid metabolism compared with WT mice.

Zinc finger protein 263 promotes colorectal cancer cell progression by activating STAT3 and enhancing chemoradiotherapy resistance.

Zinc finger protein 263 (ZNF263) is frequently upregulated in various tumor types; however, its function and regulatory mechanism in colorectal cancer (CRC) have not yet been elucidated. In this study, the expression of ZNF263 was systematically examined using data from The Cancer Genome Atlas database and samples from patients with CRC. The results indicated that high expression of ZNF263 in CRC tissues is significantly associated with tumor grade, lymph node metastasis and disant metastasis. Additionally, overexpression of ZNF263 significantly promoted the proliferation, invasion, migration, and epithelial-mesenchymal transition of CRC cells, while also increasing signal transducer and activator of transcription 3 (STAT3) expression and mRNA stability. Conversely, knockdown of ZNF263 inhibited the malignant behavior of CRC cells and decreased STAT3 expression and mRNA stability. Further mechanism studies using chromatin immunoprecipitation (CHIP) and luciferase assays verified that ZNF263 directly binds to the STAT3 promoter. Rescue experiments demonstrated that the knockdown or overexpression of STAT3 could significantly reverse the effects of ZNF263 on CRC cells. Additionally, our study found that overexpression of ZNF263 enhanced the resistance of CRC cells to the chemoradiotherapy. In summary, this study not only elucidated the significant role of ZNF263 in CRC but also proposed novel approaches and methodologies for the diagnosis and treatment of this malignancy.

Rifaximin ameliorates influenza A virus infection-induced lung barrier damage by regulating gut microbiota.

Prior research has indicated that the gut-lung-axis can be influenced by the intestinal microbiota, thereby impacting lung immunity. Rifaximin is a broad-spectrum antibacterial drug that can maintain the homeostasis of intestinal microflora. In this study, we established an influenza A virus (IAV)-infected mice model with or without rifaximin supplementation to investigate whether rifaximin could ameliorate lung injury induced by IAV and explore the molecular mechanism involved. Our results showed that IAV caused significant weight loss and disrupted the structure of the lung and intestine. The analysis results of 16S rRNA and metabolomics indicated a notable reduction in the levels of probiotics Lachnoclostridium, Ruminococcaceae_UCG-013, and tryptophan metabolites in the fecal samples of mice infected with IAV. In contrast, supplementation with 50 mg/kg rifaximin reversed these changes, including promoting the repair of the lung barrier and increasing the abundance of Muribaculum, Papillibacter and tryptophan-related metabolites content in the feces. Additionally, rifaximin treatment increased ILC3 cell numbers, IL-22 level, and the expression of RORγ and STAT-3 protein in the lung. Furthermore, our findings demonstrated that the administration of rifaximin can mitigate damage to the intestinal barrier while enhancing the expression of AHR, IDO-1, and tight junction proteins in the small intestine. Overall, our results provided that rifaximin alleviated the imbalance in gut microbiota homeostasis induced by IAV infection and promoted the production of tryptophan-related metabolites. Tryptophan functions as a signal to facilitate the activation and movement of ILC3 cells from the intestine to the lung through the AHR/STAT3/IL-22 pathway, thereby aiding in the restoration of the barrier. KEY POINTS: • Rifaximin ameliorated IAV infection-caused lung barrier injury and induced ILC3 cell activation. • Rifaximin alleviated IAV-induced gut dysbiosis and recovered tryptophan metabolism. • Tryptophan mediates rifaximin-induced ILC3 cell activation via the AHR/STAT3/IL-22 pathway.

Increased Expression of the Neuropeptides PACAP/VIP in the Brain of Mice with CNS Targeted Production of IL-6 Is Mediated in Part by Trans-Signalling.

Inflammation with expression of interleukin 6 (IL-6) in the central nervous system (CNS) occurs in several neurodegenerative/neuroinflammatory conditions and may cause neurochemical changes to endogenous neuroprotective systems. Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are two neuropeptides with well-established protective and anti-inflammatory properties. Yet, whether PACAP and VIP levels are altered in mice with CNS-restricted, astrocyte-targeted production of IL-6 (GFAP-IL6) remains unknown. In this study, PACAP/VIP levels were assessed in the brain of GFAP-IL6 mice. In addition, we utilised bi-genic GFAP-IL6 mice carrying the human sgp130-Fc transgene (termed GFAP-IL6/sgp130Fc mice) to determine whether trans-signalling inhibition rescued PACAP/VIP changes in the CNS. Transcripts and protein levels of PACAP and VIP, as well as their receptors PAC1, VPAC1 and VPAC2, were significantly increased in the cerebrum and cerebellum of GFAP-IL6 mice vs. wild type (WT) littermates. These results were paralleled by a robust activation of the JAK/STAT3, NF-κB and ERK1/2MAPK pathways in GFAP-IL6 mice. In contrast, co-expression of sgp130Fc in GFAP-IL6/sgp130Fc mice reduced VIP expression and activation of STAT3 and NF-κB pathways, but it failed to rescue PACAP, PACAP/VIP receptors and Erk1/2MAPK phosphorylation. We conclude that forced expression of IL-6 in astrocytes induces the activation of the PACAP/VIP neuropeptide system in the brain, which is only partly modulated upon IL-6 trans-signalling inhibition. Increased expression of PACAP/VIP neuropeptides and receptors may represent a homeostatic response of the CNS to an uncontrolled IL-6 synthesis and its neuroinflammatory consequences.

Natural Product-Inspired Discovery of Naphthoquinone-Furo-Piperidine Derivatives as Novel STAT3 Inhibitors for the Treatment of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and STAT3 has emerged as an effective drug target for TNBC treatment. Herein, we employed a scaffold-hopping strategy of natural products to develop a series of naphthoquinone-furopiperidine derivatives as novel STAT3 inhibitors. The in vitro assay showed that compound 10g possessed higher antiproliferative activity than Cryptotanshinone and Napabucasin against TNBC cell lines, along with lower toxicity and potent antitumor activity in a TNBC xenograft model. Mechanistically, 10g could inhibit the phosphorylation of STAT3 and the binding affinity was determined by the SPR assay (KD = 8.30 µM). Molecule docking studies suggested a plausible binding mode between 10g and the SH2 domain, in which the piperidine fragment and the terminal hydroxy group of 10g played an important role in demonstrating the success of this evolution strategy. These findings provide a natural product-inspired novel STAT3 inhibitor for TNBC treatment.