BRAF V600 inhibitors are clinically approved for the treatment of BRAFV600-mutant melanoma in combination with a MEK inhibitor, but are ineffective in other melanoma subtypes. Moreover, pan-RAF inhibitors, such as belvarafenib, when combined with MEK inhibitors (cobimetinib), have promising but limited efficacy in non-BRAF-mutant melanomas. Here, we report that the mTOR inhibitor sapanisertib improves the efficacy of combined belvarafenib and cobimetinib therapy in NRAS, NF1, and KIT-mutant melanomas. Mechanistically, sapanisertib combined with belvarafenib and cobimetinib suppressed ATF4 expression and its target gene MTHFD2 while inducing DNA damage, revealing a previously underappreciated role of the ATF4-MTHFD2 axis in DNA damage repair and drug response. Human and murine models resistant to combined belvarafenib and cobimetinib exhibited elevated levels of ATF4 and MTHFD2 and were sensitive to sapanisertib. This study provides promising treatment opportunities for patients with non-BRAF-mutant melanomas, or those who relapse following belvarafenib and cobimetinib combination therapy.
Uveal melanoma (UM) is an eye cancer that is fatal upon metastasis to the liver. Most treatments trialed in UM fail to provide therapeutic benefit; thus, there is an urgent need for novel treatment strategies. The MAPK and PI3K signaling pathways, key molecular drivers found to be hyper-activated in UM, converge on the MNK1/2-eIF4E and mTORC1/2-4EBP axes. Here, we demonstrate that the pharmacologic inhibition of MNK1/2 in combination with an mTOR inhibitor impairs clonogenic outgrowth and UM cell invasion. Using proteomic analyses, we reveal that combined MNK1/2 and mTOR inhibition disrupts ER-to-Golgi protein vesicle trafficking mainly due to downregulated RAB1A expression, a master regulator of intracellular protein transport. We further uncover that the knockdown of RAB1A blocks liver metastasis, a result that is recapitulated by combined pharmacologic inhibition of MNK1/2 and mTOR. Finally, we show that RAB1A expression reshapes the surfaceome by increasing the abundance of plasma membrane proteins associated with poor overall survival in UM, highlighting its potential as a biomarker. This study identifies protein vesicle transport as an unrecognized vulnerability in UM and supports a mechanistic rationale for targeting MNK1/2 and mTOR in metastatic UM.
Sjögren’s syndrome (SS) is a chronic autoimmune disorder that primarily affects the exocrine glands. Due to the intricate nature of the disease progression, the exact mechanisms underlying SS are not completely understood. Recent research has highlighted the complex interplay between immune dysregulation and metabolic abnormalities in inflammatory diseases. Notably, lipid metabolism has emerged as a crucial factor in the modulation of immune function and the progression of autoimmune diseases, including SS. This review explores the prevalence of dyslipidemia in SS, emphasizing its role in the onset, progression, and prognosis of the disease. We specifically described the impact of altered lipid metabolism in exocrine glands and its association with disease-specific features, including inflammation and glandular dysfunction. Additionally, we discussed the potential clinical implications of lipid metabolism regulation, including the role of polyunsaturated fatty acids (PUFAs) and their deficits in SS pathogenesis. By identifying lipid metabolism as a promising therapeutic target, this review highlights the need for further research into lipid-based interventions for the management of SS.
Primary Sjögren's syndrome (pSS) is an autoimmune disease that targets exocrine glands, leading to exocrine dysfunction. Due to its propensity to infect epithelial and B cells, Epstein-Barr virus (EBV) is hypothesized to be related with pSS. Through molecular mimicry, the synthesis of specific antigens, and the release of inflammatory cytokines, EBV contributes to the development of pSS. Lymphoma is the most lethal outcome of EBV infection and the development of pSS. As a population-wide virus, EBV has had a significant role in the development of lymphoma in people with pSS. In the review, we will discuss the possible causes of the disease.
Melanomas reprogram their metabolism to rapidly adapt to therapy-induced stress conditions, allowing them to persist and ultimately develop resistance. We report that a subpopulation of melanoma cells tolerate MAPK pathway inhibitors (MAPKis) through a concerted metabolic reprogramming mediated by peroxisomes and UDP-glucose ceramide glycosyltransferase (UGCG). Compromising peroxisome biogenesis, by repressing PEX3 expression, potentiated the proapoptotic effects of MAPKis via an induction of ceramides, an effect limited by UGCG-mediated ceramide metabolism. Cotargeting PEX3 and UGCG selectively eliminated a subset of metabolically active, drug-tolerant CD36+ melanoma persister cells, thereby sensitizing melanoma to MAPKis and delaying resistance. Increased levels of peroxisomal genes and UGCG were found in patient-derived MAPKi-relapsed melanomas, and simultaneously inhibiting PEX3 and UGCG restored MAPKi sensitivity in multiple models of therapy resistance. Finally, combination therapy consisting of a newly identified inhibitor of the PEX3-PEX19 interaction, a UGCG inhibitor, and MAPKis demonstrated potent antitumor activity in preclinical melanoma models, thus representing a promising approach for melanoma treatment.
Melanomas reprogram their metabolism to rapidly adapt to therapy-induced stress conditions, allowing them to persist and ultimately develop resistance. We report that a subpopulation of melanoma cells tolerate MAPK pathway inhibitors (MAPKi) through a concerted metabolic reprogramming mediated by peroxisomes and UDP-glucose ceramide glycosyltransferase (UGCG). Compromising peroxisome biogenesis, by repressing PEX3 expression, potentiates the pro-apoptotic effects of MAPKi via an induction of ceramides, an effect limited by UGCG-mediated ceramide metabolism. Co-targeting PEX3 and UGCG selectively eliminates a subset of metabolically active, drug-tolerant CD36 + melanoma persister cells, thereby sensitizing melanoma to MAPKi and delaying resistance. Increased levels of peroxisomal genes and UGCG are found in patient-derived MAPKi-relapsed melanomas, and simultaneously inhibiting PEX3 and UGCG restores MAPKi sensitivity in multiple models of therapy resistance. Finally, triple therapy comprised of a newly identified inhibitor of the PEX3-PEX19 interaction, a UGCG inhibitor and a MAPKi demonstrates potent anti-tumor activity in pre-clinical melanoma models, thus representing a promising approach for melanoma treatment. Highlights Inhibiting peroxisome biogenesis uncovers a metabolic vulnerability in melanoma CD36 + persister melanoma cells tolerate MAPK-targeted therapy through peroxisome/UGCG mediated metabolic rewiring Dual blockade of PEX3 and UGCG potentiates melanoma response to MAPK-targeted therapies and restores therapeutic sensitivity in MAPKi-resistant tumors NNC 55-0396 is a PEX3-PEX19 binding inhibitor with potent anti-tumor activity in melanoma
γ-Tocotrienol (GT3), a member of the vitamin E family, is well known for its medicinal value in clinical treatments. However, the role of GT3 in T helper 17 (Th17)/regulatory T cell (Treg) differentiation and function is not fully understood. Here, we demonstrated that GT3 suppressed Th17 differentiation in vitro by inhibiting signal transducer and activator of transcription 3 (STAT3) phosphorylation in the interleukin 6 (IL-6)/Janus kinase (JAK)/STAT3 signaling pathway. GT3 also inhibited HIF1A expression in Th17 metabolism. Additionally, we showed that GT3 treatment inhibited disease aggravation in an imiquimod (IMQ)-induced psoriasis-like mouse model by reducing the percentage of Th17 cells in the spleen in vivo. The findings of this study demonstrated the effects of GT3 on Th17 cells through the STAT3 signaling pathway.
Epigallocatechin-3 gallate (EGCG) is a polyphenolic component of tea and has potential curative effects in patients with autoimmune diseases. Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system (CNS). It remains unknown whether EGCG can regulate macrophage subtypes in MS. Here we evaluated the effects of EGCG in experimental autoimmune encephalomyelitis (EAE), MS mouse model. We found that EGCG treatment reduced EAE severity and macrophage inflammation in the CNS. Moreover, EAE severity was well correlated with the ratio of M1 to M2 macrophages, and EGCG treatment suppressed M1 macrophage-mediated inflammation in spleen. In vitro experiments showed that EGCG inhibited M1 macrophage polarization, but promoted M2 macrophage polarization. These effects were likely to be related to the inhibition of nuclear factor-κB signaling and glycolysis in macrophages by EGCG in macrophages. Overall, these findings provided important insights into the mechanisms through which EGCG may mediate MS.
CD4+ T cells play a vital role in the adaptive immune system and are involved in the pathogenesis of many diseases, including cancer, autoimmune diseases, and chronic inflammation. As an important mechanism for energy storage, a lot of researches have clarified that metabolism imbalance interacts with immune disorder, and one leads to the other. Lipid metabolism has close relationship with CD4+ T cells. In this review, we discuss fatty acid, cholesterol, prostaglandin, and phospholipid metabolism in CD4+ T cell subsets. Fatty acid β-oxidation (FAO) is activated in Th17 cell to support the proinflammatory function. Cholesterol promotes Th1, Th2, and Treg cell differentiation. In addition to glucose metabolism, lipid metabolism is also very important for immunity. Here, it is highlighted that lipid metabolism regulates CD4+ T cell differentiation and function and is related to diseases.
目的·探讨miR-322-5p靶向Akt3抑制Th17分化对干扰素 β(interferon-β,IFN-β)干预实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)的影响.方法·建立EAE小鼠模型,设IFN-β 干预组和PBS对照组.流式染色比较2组Th17的比例变化;RNA芯片检测2组小鼠miRNA的差异表达,筛选出miR-322-5p做进一步研究;软件预测miR-322-5p的靶基因为Akt3;IFN-β 干预后和过表达miR-322-5p后检测Akt3的表达水平;双荧光素酶报告实验验证miR-322-5p和Akt3的直接靶向关系;体外实验观察Akt3对Th17细胞分化的影响.结果 ·IFN-β 干预组的EAE小鼠Th17比例均显著降低,miR-322-5p的表达显著升高,而Akt3的表达明显降低;过表达miR-322-5p能显著抑制Akt3的表达,双荧光素酶报告实验显示Akt3是miR-322-5p的直接靶基因,且Akt3对Th17的体外分化有明显促进作用.结论 ·IFN-β 可通过影响miR-322-5p靶向Akt3,进而抑制Th17分化来缓解EAE的疾病进程.
In our previous article entitled “Low-intensity walking as mild medication for pressure control in prehypertensive and hyperten-sive subjects: how far shall we wander?” published in this journal [1], we reported mild but significant reductions in both blood pressure (BP) and heart rate (HR) after low-intensity walking at a speed of 3 km/h (2.5 metabolic equivalents of task, METs), accompanied by a transient elevation in urine β-endorphin. In a recent study observing environmental influence on low-intensity walking, we found unexpectedly interesting results that we would like to share with the readers of the journal.
作为一种形态和功能独特的白细胞亚群,巨噬细胞在机体免疫反应中发挥重要作用.巨噬细胞可分为M1型与M2型,前者促进炎症反应并抑制肿瘤细胞增殖,后者促进其增殖和组织修复.表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)是绿茶中茶多酚的主要组成部分之一,它能够减少氧化应激和组织损伤,降低肿瘤和心血管疾病等的风险.研究发现EGCG对巨噬细胞有着广泛的影响.文章就巨噬细胞不同亚型与疾病关系以及EGCG通过影响巨噬细胞以治疗疾病的研究进展作一综述.