Aging Increases Hippocampal DUSP2 by a Membrane Cholesterol Loss-Mediated RTK/p38MAPK Activation Mechanism

DUSP2 affects bladder cancer prognosis by down-regulating MEK/ERK and P38 MAPK signaling pathways through PTPN7

BACKGROUND

As one of the leading causes of cancer death worldwide, bladder cancer (BCa) ranks 12th in incidence rate. Dual Specific Phosphatase 2 (DUSP2) is a member of the bispecific protein phosphatase subfamily. DUSP2 is closely related to the prognosis of cancer, but the role of DUSP2 in bladder cancer is still unclear. This study aims to explore how DUSP2 affects the prognosis of bladder cancer and clarify the important mechanism in bladder cancer.

METHODS

Bioinformatics and experiments have detected the anti-tumor effect of DUSP2. Construct a DUSP2 overexpression cell model, and then use protein blotting experiments to verify the efficiency of transfection. The effects of DUSP2 on proliferation, metastasis, apoptosis, epithelial mesenchymal transition (EMT) and immune invasion of bladder cancer cells were detected in vitro or in vivo. In addition, the mechanism of DUSP2 regulating MEK/ERK through PTPN7 pathway and P38 MAPK inhibiting the progression of bladder cancer was also discussed.

RESULTS

The expression of DUSP2 was down regulated in bladder cancer samples and cell lines. The overexpression of DUSP2 inhibits the proliferation, metastasis and immune microenvironment of bladder cancer cells. In addition, we confirmed that DUSP2 regulates MEK/ERK and P38 MAPK through PTPN7 pathway to inhibit the progression of bladder cancer.

CONCLUSION

DUSP2 inhibits the progression of bladder cancer by regulating PTPN7. These results suggest that DUSP2/PTPN7/MEK/ERK pathway may become a new therapeutic target for bladder cancer.

p38MAPK Signaling Pathway in Osteoarthritis: Pathological and Therapeutic Aspects

Osteoarthritis (OA) is an aging-related joint disease, pathologically featured with degenerated articular cartilage and deformation of subchondral bone. OA has become the fourth major cause of disability in the world, imposing a huge economic burden. At present, the pathogenesis and pathophysiology of OA are still unclear. Complex regulating networks containing different biochemical signaling pathways are involved in OA pathogenesis and progression. The p38MAPK signaling pathway is a member of the MAPK signaling pathway family, which participates in the induction of cellular senescence, the differentiation of chondrocytes, the synthesis of matrix metalloproteinase (MMPs) and the production of pro-inflammatory factors. In recent years, studies on the regulating role of p38MAPK signaling pathway and the application of its inhibitors have attracted growing attention, with an increasing number of in vivo and in vitro studies. One interesting finding is that the inhibition of p38MAPK could suppress chondrocyte inflammation and ameliorate OA, indicating its therapeutic role in OA treatment. Based on this, we reviewed the mechanisms of p38MAPK signaling pathway in the pathogenesis of OA, hoping to provide new ideas for future research and OA treatment.

Increased exosome secretion in neurons aging in vitro by NPC1-mediated endosomal cholesterol buildup

The present study unveils the molecular mechanism through which neurons in vitro compensate age-associated proteostasis defects by increasing exosome release.

As neurons age, they show a decrease in their ability to degrade proteins and membranes. Because undegraded material is a source of toxic products, defects in degradation are associated with reduced cell function and survival. However, there are very few dead neurons in the aging brain, suggesting the action of compensatory mechanisms. We show in this work that ageing neurons in culture show large multivesicular bodies (MVBs) filled with intralumenal vesicles (ILVs) and secrete more small extracellular vesicles than younger neurons. We also show that the high number of ILVs is the consequence of the accumulation of cholesterol in MVBs, which in turn is due to decreased levels of the cholesterol extruding protein NPC1. NPC1 down-regulation is the consequence of a combination of upregulation of the NPC1 repressor microRNA 33, and increased degradation, due to Akt-mTOR targeting of NPC1 to the phagosome. Although releasing more exosomes can be beneficial to old neurons, other cells, neighbouring and distant, can be negatively affected by the waste material they contain.

Investigating the Multitarget Mechanism of Traditional Chinese Medicine Prescription for Cancer-Related Pain by Using Network Pharmacology and Molecular Docking Approach

Gu-tong formula (GTF) has achieved good curative effects in the treatment of cancer-related pain. However, its potential mechanisms have not been explored. We used network pharmacology and molecular docking to investigate the molecular mechanism and the effective compounds of the prescription. Through the analysis and research in this paper, we obtained 74 effective compounds and 125 drug-disease intersection targets to construct a network, indicating that quercetin, kaempferol, and β-sitosterol were possibly the most important compounds in GTF. The key targets of GTF for cancer-related pain were Jun proto-oncogene (JUN), mitogen-activated protein kinase 1 (MAPK1), and RELA proto-oncogene (RELA). 2204 GO entries and 148 pathways were obtained by GO and KEGG enrichment, respectively, which proved that chemokine, MAPK, and transient receptor potential (TRP) channels can be regulated by GTF. The results of molecular docking showed that stigmasterol had strong binding activity with arginine vasopressin receptor 2 (AVPR2) and C-X3-C motif chemokine ligand 1 (CX3CL1) and cholesterol was more stable with p38 MAPK, prostaglandin-endoperoxide synthase 2 (PTGS2), and transient receptor potential vanilloid-1 (TRPV1). In conclusion, the therapeutic effect of GTF on cancer-related pain is based on the comprehensive pharmacological effect of multicomponent, multitarget, and multichannel pathways. This study provides a theoretical basis for further experimental research in the future.