TJ-M2010-5, A self-developed MyD88 inhibitor, attenuates liver fibrosis by inhibiting the NF-κB pathway

Lipopolysaccharide Induces Resistance to CAR-T Cell Therapy of Colorectal Cancer Cells through TGF-β-Mediated Stemness Enhancement

Chimeric antigen receptor-T (CAR-T) cell therapy is a cellular immunotherapy that has emerged in recent years, and increasing studies showed that therapeutic resistance to CAR-T cell therapy presents in colorectal cancer patients. Lipopolysaccharide (LPS), a component of the cell wall of Gram-negative bacteria, is known to preserve a high concentration in the colon. Whether LPS is a contributing factor to the development of resistance in colorectal cancer cells against CAR-T cell therapy remains unclear. For in vivo experiments, colorectal cancer cells COLO205 were pretreated with LPS for 24 h and then were injected into nude mice through the tail vein, followed by CAR-T cells transplantation one day later. Later, the number of tumors in the lung tissues of the mice was observed. The in vitro experiments were performed on COLO205 cells, which were treated with LPS for 24 h. The effect of LPS on the stemness of COLO205 and SW620 cells was observed by using the colony formation assay and spheroidization experiments. The effect of LPS on the expression of stemness-related genes, including CD44, SOX2, and NANOG, was observed by qRT-PCR assay, Western blotting assay, and immunofluorescence staining. Inhibitors of TGF-β and the MYD88 inhibitor were used to study the mechanisms by which LPS induces the stemness enhancement and resistance to CAR-T cell therapy of COLO205 cells. The correlation between MYD88 and TGFB1, as well as the correlation between TGFB1 and stemness-related genes was analyzed using the TCGA database. Both the in vivo assay of nude mice and the in vitro assay showed that LPS pretreatment could induce resistance to CAR-T cell therapy of colorectal cancer cells. LPS could enhance COLO205 and SW620 cells stemness presented by upregulation of CD44, SOX2, and NANOG. The reverse interfering assay using the TGF-β inhibitor indicated that the autosecretion of TGF-β induced by LPS played a critical role in the stemness enhancement of colorectal cancer cells. The TCGA database analysis revealed a strong positive correlation between MYD88 and TGFB1. Additionally, TGFB1 has been found to upregulate the expression of genes associated with stemness. Further mechanism studies showed that the TLR4/MYD88 pathway medicates LPS-induced TGF-β expression. Our results suggested that LPS-induced resistance to CAR-T cell therapy of colorectal cancer cells through stemness enhancement. TLR4/MYD88 signal pathway-dependent TGF-β expression was involved in stemness enhancement and CAR-T cell therapy resistance. In conclusion, our findings help us to understand the underlying mechanisms of CAR-T cell therapy resistance and indicate that inhibitors of TGF-β and MYD88 are promising targeting candidates to promote a therapeutic effect of CAR-T cell therapy in colorectal cancer in the clinic.

Inhibition of the MyD88/NF-κB pathway alters the Th1/Th2 balance to exacerbate liver injury and hepatic fibrosis in alveolar echinococcosis

Alveolar echinococcosis (AE) is a severe human-veterinary parasitic disease. However, the Myeloid differentiation factor 88 (MyD88) signaling pathway has seldom been explored in the context of AE. Protoscoleces (PSC) of alveolar echinococcosis were obtained from the liver tissues of gerbils for breeding purposes, and then used to establish a mouse model of alveolar echinococcosis. This mouse model was utilized to block the MyD88 signaling pathway, with the aim of analyzing the associated fibrotic and inflammatory responses. To evaluate the expression of fibrotic molecules, Masson staining and Quantitative reverse transcription polymerase chain reaction (qRT-PCR) were performed. Moreover, qRT-PCR and Western blotting (WB) were adopted to investigate the alterations in the protein expression levels of MyD88 and Nuclear factor-κB p65 (NF-κB p65). In parallel, the human monocyte cell line RAW 264.7was cultured in vitro. After stimulation of RAW 264.7 with Echinococcus multilocularis protein (Emp), the MyD88 signaling pathway was blocked using TJ-M2010-5. Subsequently, the protein and mRNA expression levels of MyD88 and NF-κB p65 were determined by WB and qRT-PCR, respectively, while the dynamic changes in the proportion of macrophages were monitored by flow cytometry. The results demonstrated that the compound TJ-M2010-5 could effectively suppress the MyD88 signaling pathway, leading to a significant down-regulation of the expression levels of both MyD88 and Nuclear factor-κB p65 (NF-κB p65). Moreover, the blockade of the MyD88 signaling pathway perturbed the balance of the Th1/Th2 immune response. Consequently, this imbalance further aggravated liver fibrosis and liver injury. The blockade of the MyD88 signaling pathway led to a disruption of the balance among T-lymphocyte subpopulations, an enhancement of Th2 type immune responses, and a reduction in pro-inflammatory responses. These alterations ultimately culminated in aggravated liver injury and fibrosis in the context of alveolar echinococcosis.

Inhibition of the MyD88 signaling pathway could upregulates Ghrelin expression to synergistically regulate hepatic Echinococcus multilocularis-infected progression

Introduction

AE and whether the inhibition of the MyD88 inflammatory pathway can enhance Ghrelin expression to collaboratively modulate AE progression remains unclear.

Methods

In this study, we evaluated Ghrelin serum levels and changes in TLR4/MyD88/NF-κB pathway proteins and inflammatory factors in AE patients and E. multilocularis mouse models at different stages of infection (-4, -8, and -12 weeks). Additionally, we administered the MyD88 inhibitor TJ-M2010-5 intraperitoneally to infected mice to evaluate alterations in inflammation and Ghrelin levels, as well as disease progression.

Results

A decrease in serum Ghrelin levels in AE patients, whereas both Ghrelin and GHSR, along with TLR4/MyD88/NF-κB pathway proteins and markers of M1/M2 macrophage polarization, exhibited increased expression in the inflammatory cell zones surrounding hepatic lesions. Similar findings were observed in E. multilocularis-infected mice. M1-type inflammatory expression predominated throughout the infection's progression, with sustained high levels of Ghrelin counteracting inflammation. The TLR4/ MyD88/NF-κB pathway remained suppressed during the first 8 weeks, becoming activated only at 12 weeks. Inhibition of the MyD88 pathway resulted in reduced inflammation levels and upregulated Ghrelin expression, thereby collaboratively regulating the progression of hepatic infection.

Conclusion

These findings suggest an interactive regulation between the MyD88 inflammatory signaling pathway and Ghrelin, indicating that MyD88 inhibition could enhance Ghrelin expression to modulate the progression of E. multilocularis infection.

Signaling pathways that activate hepatic stellate cells during liver fibrosis

Liver fibrosis is a complex process driven by various factors and is a key feature of chronic liver diseases. Its essence is liver tissue remodeling caused by excessive accumulation of collagen and other extracellular matrix. Activation of hepatic stellate cells (HSCs), which are responsible for collagen production, plays a crucial role in promoting the progression of liver fibrosis. Abnormal expression of signaling pathways, such as the TGF-β/Smads pathway, contributes to HSCs activation. Recent studies have shed light on these pathways, providing valuable insights into the development of liver fibrosis. Here, we will review six signaling pathways such as TGF-β/Smads that have been studied more in recent years.

MyD88 and Its Inhibitors in Cancer: Prospects and Challenges

The interplay between the immune system and cancer underscores the central role of immunotherapy in cancer treatment. In this context, the innate immune system plays a critical role in preventing tumor invasion. Myeloid differentiation factor 88 (MyD88) is crucial for innate immunity, and activation of MyD88 promotes the production of inflammatory cytokines and induces infiltration, polarization, and immune escape of immune cells in the tumor microenvironment. Additionally, abnormal MyD88 signaling induces tumor cell proliferation and metastasis, which are closely associated with poor prognosis. Therefore, MyD88 could serve as a novel tumor biomarker and is a promising target for cancer therapy. Current strategies targeting MyD88 including inhibition of signaling pathways and protein multimerization, have made substantial progress, especially in inflammatory diseases and chronic inflammation-induced cancers. However, the specific role of MyD88 in regulating tumor immunity and tumorigenic mechanisms remains unclear. Therefore, this review describes the involvement of MyD88 in tumor immune escape and disease therapy. In addition, classical and non-classical MyD88 inhibitors were collated to provide insights into potential cancer treatment strategies. Despite several challenges and complexities, targeting MyD88 is a promising avenue for improving cancer treatment and has the potential to revolutionize patient outcomes.

Innate immune modulation in transplantation: mechanisms, challenges, and opportunities

Organ transplantation is characterized by a sequence of steps that involve operative trauma, organ preservation, and ischemia-reperfusion injury in the transplant recipient. During this process, the release of damage-associated molecular patterns (DAMPs) promotes the activation of innate immune cells via engagement of the toll-like receptor (TLR) system, the complement system, and coagulation cascade. Different classes of effector responses are then carried out by specialized populations of macrophages, dendritic cells, and T and B lymphocytes; these play a central role in the orchestration and regulation of the inflammatory response and modulation of the ensuing adaptive immune response to transplant allografts. Organ function and rejection of human allografts have traditionally been studied through the lens of adaptive immunity; however, an increasing body of work has provided a more comprehensive picture of the pivotal role of innate regulation of adaptive immune responses in transplant and the potential therapeutic implications. Herein we review literature that examines the repercussions of inflammatory injury to transplantable organs. We highlight novel concepts in the pathophysiology and mechanisms involved in innate control of adaptive immunity and rejection. Furthermore, we discuss existing evidence on novel therapies aimed at innate immunomodulation and how this could be harnessed in the transplant setting.

Integration of MyD88 inhibitor into mesoporous cerium oxide nanozymes-based targeted delivery platform for enhancing treatment of ulcerative colitis

Excessive reactive oxygen species (ROS) and stressed inflammatory response are major characteristics of ulcerative colitis, which cause disease progression and aggravation. Herein, a novel mesoporous cerium oxide nanozymes (MCN) was designed and then loaded with Myeloid differentiation factor-88 (MyD88) inhibitor for synergistic treatment of colitis by scavenging ROS and regulating inflammation. This innovative MCN with average particle size of 200.7 nm, specific surface area of 119.78 m2/g and mesopores of 4.47 nm not only exhibited excellent SOD-like and CAT-like activities to scavenge ROS but also could act as a carrier to load MyD88 inhibitor, TJ-M2010-5, (abbreviated as TJ-5) into their mesopores, achieving the effect of 'two birds with one stone'. Besides, the modification of dextran sulfate sodium (TJ-5/MCN/DSS) increased the internalization of nanozymes into activated macrophages and enhanced in vitro anti-inflammatory ability. To enhance colon targeting, we coated TJ-5/MCN/DSS with the enteric material Eudragit S100, preventing premature release or absorption of the drug in the gastrointestinal tract after oral administration. The results demonstrated that TJ-5/MCN/DSS/Eudragit not only achieved delayed drug release and improved colon targeting but also exhibited optimal therapeutic efficacy in colitis mice. Mechanistically, the MCN-mediated ROS scavenging and TJ-5-mediated MyD88 blockade synergistically inhibited the NF-κB signaling pathway, thereby reducing the inflammatory response. Importantly, TJ-5/MCN/DSS/Eudragit did not induce systemic toxicity. In conclusion, our work not only presents a novel carrier capable of scavenging ROS but also provides proof of concept for the synergistic treatment of colitis using this carrier in combination with MyD88 inhibitors. This study proposes a safe and efficient strategy for targeting ROS-associated inflammation.

Expression and Function of BMP and Activin Membrane-Bound Inhibitor (BAMBI) in Chronic Liver Diseases and Hepatocellular Carcinoma

BAMBI (bone morphogenetic protein and activin membrane-bound inhibitor) is a transmembrane pseudoreceptor structurally related to transforming growth factor (TGF)-β type 1 receptors (TGF-β1Rs). BAMBI lacks a kinase domain and functions as a TGF-β1R antagonist. Essential processes such as cell differentiation and proliferation are regulated by TGF-β1R signaling. TGF-β is the best-studied ligand of TGF-βRs and has an eminent role in inflammation and fibrogenesis. Liver fibrosis is the end stage of almost all chronic liver diseases, such as non-alcoholic fatty liver disease, and at the moment, there is no effective anti-fibrotic therapy available. Hepatic BAMBI is downregulated in rodent models of liver injury and in the fibrotic liver of patients, suggesting that low BAMBI has a role in liver fibrosis. Experimental evidence convincingly demonstrated that BAMBI overexpression is able to protect against liver fibrosis. Chronic liver diseases have a high risk of hepatocellular carcinoma (HCC), and BAMBI was shown to exert tumor-promoting as well as tumor-protective functions. This review article aims to summarize relevant studies on hepatic BAMBI expression and its role in chronic liver diseases and HCC.

Interleukin-19 upregulates fibronectin and collagen I expression via the NF-κB-Smad2/3 pathway in fibroblasts of patients with chronic rhinosinusitis

BACKGROUND

Tissue remodeling is a prominent characteristic of chronic rhinosinusitis (CRS). Excess deposition of fibronectin (FN) and collagen (Col) I by fibroblasts is crucial for the pathologic tissue remodeling in CRS without nasal polyps (CRSsNP). Increased interleukin (IL)-19 level in patients with CRS had been demonstrated in our previous studies. Here, we aimed to evaluate the role of IL-19 in mediating FN and Col I expression in CRS.

METHODS

Nasal mucosal tissue samples were collected from patients with CRS with nasal polyps (CRSwNP), CRSsNP, and controls. The expression of IL-19, vimentin, FN, and Col I were detected using immunohistochemistry and immunofluorescence. Primary human nasal fibroblasts were treated with IL-19, then the activation of Smad2/3, NF-κB and relevant pathways, and the expression of FN and Col I were measured.

RESULTS

Expression levels of vimentin, FN, and Col I were significantly increased in nasal tissues from patients with CRSsNP compared with CRSwNP and control subjects. Moreover, IL-19 co-localized with FN and Col Ι in nasal tissues. IL-19-treated fibroblasts had increased production of FN and Col I, which was associated with the activated Smad2/3 and NF-κB pathways. Moreover, Smad2/3 activation was mediated by the NF-κB pathway in IL-19-treated fibroblasts.

CONCLUSIONS

IL-19 promotes FN and Col I production via the activated NF-κB-Smad2/3 pathway in fibroblasts, leading to fibrosis and collagen deposition in patients with CRS.

β-Elemene Attenuates Renal Fibrosis in the Unilateral Ureteral Obstruction Model by Inhibition of STAT3 and Smad3 Signaling via Suppressing MyD88 Expression

Renal fibrosis is a chronic pathological process that seriously endangers human health. However, the current therapeutic options for this disease are extremely limited. Previous studies have shown that signaling factors such as JAK2/STAT3, Smad3, and Myd88 play a regulatory role in renal fibrosis, and β-elemene is a plant-derived sesquiterpenoid organic compound that has been shown to have anti-inflammatory, anti-cancer, and immunomodulatory effects. In the present study, the anti-fibrotic effect of β-elemene was demonstrated by in vivo and in vitro experiments. It was shown that β-elemene inhibited the synthesis of extracellular matrix-related proteins in unilateral ureteral obstruction mice, and TGF-β stimulated rat interstitial fibroblast cells, including α-smooth muscle actin, vimentin, and connective tissue growth factor, etc. Further experiments showed that β-elemene reduced the expression levels of the above-mentioned fibrosis-related proteins by blocking the phosphorylation of JAK2/STAT3, Smad3, and the expression or up-regulation of MyD88. Notably, knockdown of MyD88 attenuated the phosphorylation levels of STAT3 and Smad3 in TGF-β stimulated NRK49F cell, which may be a novel molecular mechanism by which β-elemene affects renal interstitial fibrosis. In conclusion, this study elucidated the anti-interstitial fibrosis effect of β-elemene, which provides a new direction for future research and development of drugs related to chronic kidney disease.