Role of Luteolin as Potential New Therapeutic Option for Patients with Glioblastoma through Regulation of Sphingolipid Rheostat

Hydrogen sulfide improves depression-like behaviors in CUMS-induced mice by regulating autophagy

The pathogenesis of depression is associated with synaptic impairment and dysfunction in autophagy processes. Mendelian randomization (MR) analysis revealed that six GWAS IDs revealed a significant association between Beclin-1 levels and depression risk. Besides, all SNPs had a positive effect on depression risk. Analyzing neurons from depressed individuals using single-cell RNA sequencing (scRNA-seq) uncovered decreased expression of AKT, mTOR, and genes linked to synaptic plasticity. The activation of the PI3K/AKT/mTOR signaling has been demonstrated to control autophagy and have a protective effect on the nervous system. Hydrogen sulfide (H2S) is an endogenous gasotransmitter that can potentially treat various neurological disorders by improving neuronal synaptic plasticity. However, whether H2S regulates autophagy through PI3K/AKT/mTOR signaling, improves neuronal synaptic plasticity damage, and plays an antidepressant role is unclear. Our current research revealed that the reduction in the expression of p-PI3K, p-AKT, and p-mTOR proteins increase in neuronal autophagy activity and decline synaptic plasticity in mice with depression induced by chronic unpredictable mild stress (CUMS). Treatment with the exogenous hydrogen sulfide donor NaHS for one day and continuous treatment for one week improved the depression-like behaviors in the mice. Compared with those after one day of NaHS treatment, the above protein expression levels were restored and maintained, and the antidepressant effect was more significant after one week of continuous treatment with NaHS. Moreover, the PI3K inhibitor LY294002 was used to demonstrate that NaHS suppresses autophagy through activating the PI3K/AKT/mTOR signaling and ameliorates synaptic plasticity impairments. This study provides novel insights into the antidepressant mechanisms of H2S, highlighting its antidepressant therapeutic potential.

Triptolide's impact on ACER1 signaling: Inducing autophagy for triple-negative breast cancer suppression

Given the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (Her-2) in triple-negative breast cancer (TNBC) cells, the efficacy of targeted therapies is limited. In this study, we uncovered that triptolide (TP) effectively suppresses the migration and invasiveness of MDA-MB-231 cells by activating autophagic pathways. Western blotting analysis revealed that TP significantly reduced the expression levels of p62 protein, while simultaneously markedly increasing the expression levels of LC3B-II, BNIP3, BNIP3L, ATG5, and ULK1 proteins, strongly suggesting an enhancement of autophagic activity in the cells. Based on PCR array screening, we identified the ACER1 gene as exhibiting notable expression alterations post-TP treatment. Overexpression of ACER1 gene enhanced the TP-induced apoptosis in MDA-MB-231 cells and augmented the regulation of autophagy-related proteins p62 and LC3B-II, leading to an increase in autophagosome numbers and a marked reduction in cellular migration and invasiveness. Conversely, ACER1 gene knockdown reversed these effects. In vivo experiments demonstrated that TP effectively inhibits the growth of MDA-MB-231 xenograft tumors, concurrently upregulating ACER1 and LC3B-II expression in tumor tissues, while p62 protein levels were notably decreased. Hematoxylin and eosin (H&E) staining results indicated no evident toxicity in liver and kidney tissues of BALB/c mice at a TP dose of 0.4 mg/kg. This study, for the first time, elucidates a novel mechanism by which TP inhibits TNBC through an autophagic process mediated by ACER1.

The role of sphingolipid rheostat in the adult-type diffuse glioma pathogenesis

Gliomas are highly aggressive primary brain tumors, with glioblastoma multiforme being the most severe and the most common one. Aberrations in sphingolipid metabolism are a hallmark of glioma cells. The sphingolipid rheostat represents the balance between the pro-apoptotic ceramide and pro-survival sphingosine-1-phosphate (S1P), and in gliomas it is shifted toward cell survival and proliferation, promoting gliomas' aggressiveness, cellular migration, metastasis, and invasiveness. The sphingolipid rheostat can be altered by targeting enzymes that directly or indirectly affect the ratio of ceramide to S1P, leading to increased ceramide or decreased S1P levels. Targeting the sphingolipid rheostat offers a potential therapeutic pathway for glioma treatment which can be considered through reducing S1P levels or modulating S1P receptors to reduce cell proliferation, as well as through increasing ceramide levels to induce apoptosis in glioma cells. Although the practical translation into clinical therapy is still missing, sphingolipid rheostat targeting in gliomas has been of great research interest in recent years with several interesting achievements in the glioma therapy approach, offering hope for patients suffering from these vicious malignancies.

Ceramides-Emerging Biomarkers of Lipotoxicity in Obesity, Diabetes, Cardiovascular Diseases, and Inflammation

Abnormalities in lipid homeostasis have been associated with many human diseases, and the interrelation between lipotoxicity and cellular dysfunction has received significant attention in the past two decades. Ceramides (Cers) are bioactive lipid molecules that serve as precursors of all complex sphingolipids. Besides their function as structural components in cell and mitochondrial membranes, Cers play a significant role as key mediators in cell metabolism and are involved in numerous cellular processes, such as proliferation, differentiation, inflammation, and induction of apoptosis. The accumulation of various ceramides in tissues causes metabolic and cellular disturbances. Recent studies suggest that Cer lipotoxicity has an important role in obesity, metabolic syndrome, type 2 diabetes, atherosclerosis, and cardiovascular diseases (CVDs). In humans, elevated plasma ceramide levels are associated with insulin resistance and impaired cardiovascular and metabolic health. In this review, we summarize the role of ceramides as key mediators of lipotoxicity in obesity, diabetes, cardiovascular diseases, and inflammation and their potential as a promising diagnostic tool.

New Insights into Glioblastoma

Glioblastoma (GBM) is the most aggressive malignant primary central nervous system (CNS) tumor and, despite decades of research, it remains a lethal disease with a median overall survival of less than two years [...].