Brazilin-Ce nanoparticles attenuate inflammation by de/anti-phosphorylation of IKKß.

Inflammation is associated with a series of diseases like cancer, cardiovascular disease and infection, and phosphorylation/dephosphorylation modification of proteins are important in inflammation regulation. Here we designed and synthesized a novel Brazilin-Ce nanoparticle (BX-Ce NPs) using Brazilin, which has been used for anti-inflammation in cardiovascular diseases but with narrow therapeutic window, and Cerium (IV), a lanthanide which has the general activity in catalyzing the hydrolysis of phosphoester bonds, to conferring de/anti-phosphorylation of IKKß. We found that BX-Ce NPs specifically bound to Asn225 and Lys428 of IKKß and inhibited its phosphorylation at Ser181, contributing to appreciably anti-inflammatory effect in cellulo (IC50 = 2.5 µM). In vivo mouse models of myocardial infarction and sepsis also showed that the BX-Ce NPs significantly ameliorated myocardial injury and improved survival in mice with experimental sepsis through downregulating phosphorylation of IKKß. These findings provided insights for developing metal nanoparticles for guided ion interfere therapy, particularly synergistically target de/anti-phosphorylation as promising therapeutic agents for inflammation and related diseases.

A transient wave of Bhlhe41+ resident macrophages enables remodeling of the developing infarcted myocardium.

The immune system plays a critical role during myocardial injury, contributing to repair and remodeling post myocardial infarction (MI). The myocardial infarct and border zone exhibit high heterogeneity, in turn leading to reconstructing macrophage subsets and specific functions. Here we use a combination of single-cell RNA sequencing, spatial transcriptomes, and reporter mice to characterize temporal-spatial dynamics of cardiac macrophage subtype in response to MI. We identify that transient appearance of monocyte-derived Bhlhe41+ Mφs in the "developing" infarct zone peaked at day 7, while other monocyte-derived macrophages are identified in "old" infarct zone. Functional characterization by co-culture of Bhlhe41+ Mφs with cardiomyocytes and fibroblasts or depletion of Bhlhe41+ Mφs unveils a crucial contribution of Bhlhe41+ Mφs in suppression of myofibroblast activation. This work highlights the importance of Bhlhe41+ Mφ phenotype and plasticity in preventing excessive fibrosis and limiting the expansion of developing infarct area.

Anti-inflammatory effect of Danhong injection through inhibition of GSDMD-mediated pyroptosis.

BACKGROUND: Pyroptosis is an inflammatory form of cell death that has been implicated in various infectious and non-infectious diseases. Gasdermin family proteins are the key executors of pyroptotic cell death, thus they are considered as novel therapeutic targets for inflammatory diseases. However, only limited gasdermin specific inhibitors have been identified to date. Traditional Chinese medicines have been applied in clinic for centuries and exhibit potential in anti-inflammation and anti-pyroptosis. We attempted to find candidate Chinese botanical drugs which specifically target gasdermin D (GSDMD) and inhibit pyroptosis. METHODS: In this study, we performed high-throughput screening using a botanical drug library to identify pyroptosis specific inhibitors. The assay was based on a cell pyroptosis model induced by lipopolysaccharides (LPS) and nigericin. Cell pyroptosis levels were then evaluated by cell cytotoxicity assay, propidium iodide (PI) staining and immunoblotting. We then overexpressed GSDMD-N in cell lines to investigate the direct inhibitory effect of the drug to GSDMD-N oligomerization. Mass spectrometry studies were applied to identify the active components of the botanical drug. Finally, a mouse model of sepsis and a mouse model of diabetic myocardial infarction were constructed to verify the protective effect of the drug in disease models of inflammation. RESULTS: High-throughput screening identified Danhong injection (DHI) as a pyroptosis inhibitor. DHI remarkably inhibited pyroptotic cell death in a murine macrophage cell line and bone marrow-derived macrophages. Molecular assays demonstrated the direct blockade of GSDMD-N oligomerization and pore formation by DHI. Mass spectrometry studies identified the major active components of DHI, and further activity assays revealed salvianolic acid E (SAE) as the most potent molecule among these components, and SAE has a strong binding affinity to mouse GSDMD Cys192. We further demonstrated the protective effects of DHI in mouse sepsis and mouse myocardial infarction with type 2 diabetes. CONCLUSION: These findings provide new insights for drug development from Chinese herbal medicine like DHI against diabetic myocardial injury and sepsis through blocking GSDMD-mediated macrophage pyroptosis.

Thioredoxin-1 regulates calcium homeostasis in MPP+ /MPTP-induced Parkinson's disease models.

Disturbance in calcium (Ca2+ ) homeostasis has been involved in a variety of neuropathological conditions including Parkinson's disease (PD). The Ca2+ channel, transient receptor potential channel 1 (TRPC1), plays a protective role in regulating entry of Ca2+ activated by store depletion of Ca2+ in endoplasmic reticulum (ER). We have showed that thioredoxin-1 (Trx-1) plays a role in suppressing ER stress in PD. However, whether Trx-1 regulates TRPC1 expression in PD is still unknown. In the present study, we demonstrated that treatment of 1-methyl-4-phenylpyridinum ion (MPP+ ) significantly reduced the expression of TRPC1 in PC12 cells, which was restored by Trx-1 overexpression, and further decreased significantly by Trx-1 siRNA. Moreover, we found that Ca2+ entered into the cells was decreased by MPP+ in PC 12 cells, which was restored by Trx-1 overexpression, and further decreased by Trx-1 siRNA. MPP+ significantly increased calcium-dependent cysteine protease calpain1 expression in PC12 cells, which was suppressed by Trx-1 overexpression. Calpain1 expression was increased by Trx-1 siRNA or SKF96365, an inhibitor of TRPC1. Moreover, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) decreased TRPC1 expression in the substantia nigra pars compacta region (SNpc), which was restored in mice overexpressing Trx-1, and further decreased in mice of knockdown Trx-1. Inversely, the expression of calpain1 was increased by MPTP, which was suppressed in mice overexpressing Trx-1, and further increased in mice of knockdown Trx-1. In conclusion, Trx-1 regulates the Ca2+ entry through regulating TRPC1 expression after treatment of MPP+ /MPTP.

Thioredoxin-1 Rescues MPP+/MPTP-Induced Ferroptosis by Increasing Glutathione Peroxidase 4.

Parkinson's disease (PD), a common neurodegenerative disease, is typically associated with the loss of dopaminergic neuron in the substantia nigra pars compacta (SNpc). Ferroptosis is a newly identified cell death, which associated with iron accumulation, glutathione (GSH) depletion, lipid peroxidation formation, reactive oxygen species (ROS) accumulation, and glutathione peroxidase 4 (GPX4) reduction. It has been reported that ferroptosis is linked with PD.Thioredoxin-1 (Trx-1) is a redox regulating protein and plays various roles in regulating the activity of transcription factors and inhibiting apoptosis. However, whether Trx-1 plays the role in regulating ferroptosis involved in PD is still unknown. Our present study showed that 1-methyl-4-phenylpyridinium (MPP+) decreased cell viability, GPX4, and Trx-1, which were reversed by Ferrostatin-1 (Fer-1) in PC 12 cells and SH-SY5Y cells. Moreover, the decreased GPX4 and GSH, and increased ROS were inhibited by Fer-1 and Trx-1 overexpression. We further repeated that behavior deficits resulted from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were improved in Trx-1 overexpression transgenic mice. Trx-1 reversed the decreases of GPX4 and tyrosine hydroxylase (TH) induced by MPTP in the substantia nigra pars compacta (SNpc). Our results suggest that Trx-1 inhibits ferroptosis in PD through regulating GPX4 and GSH.