USP10 regulates macrophage inflammation responses via stabilizing NEMO in LPS-induced sepsis.

BACKGROUND: Sepsis is a systemic inflammatory response syndrome characterized by persistent inflammation and immunosuppression, leading to septic shock and multiple organ dysfunctions. Ubiquitin-specific peptidase 10 (USP10), a deubiquitinase enzyme, plays a vital role in cancer and arterial restenosis, but its involvement in sepsis is unknown. OBJECTIVE: In this study, we investigated the significance of USP10 in lipopolysaccharide (LPS)-stimulated macrophages and its biological roles in LPS-induced sepsis. METHODS: Lipopolysaccharides (LPS) were used to establish sepsis models in vivo and in vitro. We use western blot to identify USP10 expression in macrophages. Spautin-1 and USP10-siRNA were utilized for USP10 inhibition. ELISA assays were used to assess for TNF-α and IL-6 in vitro and in vivo. Nuclear and cytoplasmic protein extraction and Confocal microscopy were applied to verify the translocation of NF-κB. Mechanically, co-immunoprecipitation and rescue experiments were used to validate the regulation of USP10 and NEMO. RESULTS: In macrophages, we found that LPS induced USP10 upregulation. The inhibition or knockdown of USP10 reduced the pro-inflammatory cytokines TNF-α and IL-6 and suppressed LPS-induced NF-κB activation by regulating the translocation of NF-κB. Furthermore, we found that NEMO, the regulatory subunit NF-κB essential modulator, was essential for the regulation of LPS-induced inflammation by USP10 in macrophages. NEMO protein evidently interacted with USP10, whereby USP10 inhibition accelerated the degradation of NEMO. Suppressing USP10 significantly attenuated inflammatory responses and improved the survival rate in LPS-induced sepsis mice. CONCLUSIONS: Overall, USP10 was shown to regulate inflammatory responses by stabilizing the NEMO protein, which may be a potential therapeutic target for sepsis-induced lung injury.

Rab27a deletion impairs the therapeutic potential of endothelial progenitor cells for myocardial infarction.

Endothelial progenitor cell (EPC) transplantation has shown advantages in the treatment of myocardial infarction (MI) in animal models and clinical trials through mechanisms of direct intercellular contacts, autocrine, and paracrine. However, the effects of EPC transplantation for MI treatment remain controversial and the underlying mechanisms have not been fully elucidated. Here, we explored the role of Rab27a in the therapeutic potential of EPC transplantation in MI. We found that Rab27a knockout impaired the viability, and reduced the proliferation and tube formation function of ECPs. The recovery of cardiac function and improvement of ventricular remodeling from EPCs transplantation were significantly damaged by Rab27a deletion in vivo. Rab27a deletion inhibited the protein expression of phosphoinositide 3-kinase (PI3K) and cyclin D1 and the phosphorylation levels of Akt and FoxO3a. Therefore, Rab27a knockout suppressed the PI3K-Akt-FoxO3a/cyclin D1 signaling pathway. Furthermore, Rab27a ablation dramatically reduced exosome release in EPCs. These results demonstrated that Rab27a plays an essential role in EPC functions. The elucidation of this mechanism provides novel insights into EPC transplantation as a promising treatment for post-MI injuries.

Experimental Study on the Autogenic Acid Fluid System of a High-Temperature Carbonate Reservoir by Acid Fracturing.

As an important part of the acid fracturing process of carbonate reservoir, the performance of acid fracturing working fluid directly affects the stimulation effect of oil wells. In this paper, formaldehyde (agent A) and ammonium chloride (agent B) were used as the matrix. Several aldehydes with different volume ratios were prepared. The acid ratio with the highest acid yield was selected by the sodium hydroxide titration experiment. The results show that when the volume ratio of agent A to agent B is 1:1.3, the acid production capacity is the strongest. The pH values at several time points in the process of acid reaction were measured by a pen pH meter. The relationship curve between acid production capacity and time was obtained. The acid production capacity increased with time. It tends to be stable after a certain time. The experiment of acid rock reaction kinetics shows that the reaction rate between acid and rock decreases with the extension of time. The reaction time can reach 6 h. The reaction rate of autogenic acid under different temperatures and concentrations ranges from 6.61 × 10-7 to 9.49 × 10-7 mol/(s·cm2) within 6 h. Therefore, it indicates that the reaction time between autogenic acid and carbonate rock is long and the reaction rate is low. It is beneficial to improve the acid treatment effect of the carbonate reservoir. The conductivity experiments show that at different temperatures, with the increase of sealing pressure, the etching ability of autogenic acid decreases. The etching effect is better at 338 K. After etching, the permeability and conductivity of the rock slab of 5 MPa closure pressure are 227 D and 72.62 D·cm, respectively. To sum up, this autogenic acid is an effective working fluid in the acid fracturing process of the carbonate reservoir. It can obviously reduce the reaction rate of acid rock and has certain conductivity.

The harsh microenvironment in infarcted heart accelerates transplanted bone marrow mesenchymal stem cells injury: the role of injured cardiomyocytes-derived exosomes.

Stem cell therapy can be used to repair and regenerate damaged hearts tissue; nevertheless, the low survival rate of transplanted cells limits their therapeutic efficacy. Recently, it has been proposed that exosomes regulate multiple cellular processes by mediating cell survival and communication among cells. The following study investigates whether injured cardiomyocytes-derived exosomes (cardiac exosomes) affect the survival of transplanted bone marrow mesenchymal stem cells (BMSCs) in infarcted heart. To mimic the harsh microenvironment in infarcted heart that the cardiomyocytes or transplanted BMSCs encounter in vivo, cardiomyocytes conditioned medium and cardiac exosomes collected from H2O2-treated cardiomyocytes culture medium were cultured with BMSCs under oxidative stress in vitro. Cardiomyocytes conditioned medium and cardiac exosomes significantly accelerated the injury of BMSCs induced by H2O2; increased cleaved caspase-3/caspase-3 and apoptotic percentage, and decreased the ratio of Bcl-2/Bax and cell viability in those cells. Next, we explored the role of cardiac exosomes in the survival of transplanted BMSCs in vivo by constructing a Rab27a knockout (KO) mice model by a transcription activator-like effector nuclease (TALEN) genome-editing technique; Rab27a is a family of GTPases, which has critical role in secretion of exosomes. Male mouse GFP-modified BMSCs were implanted into the viable myocardium bordering the infarction in Rab27a KO and wild-type female mice. The obtained results showed that the transplanted BMSCs survival in infarcted heart was increased in Rab27a KO mice by the higher level of Y-chromosome Sry DNA, GFP mRNA, and the GFP fluorescence signal intensity. To sum up, these findings revealed that the injured cardiomyocytes-derived exosomes accelerate transplanted BMSCs injury in infarcted heart, thus highlighting a new mechanism underlying the survival of transplanted cells after myocardial infarction.

MiRNA-543 promotes osteosarcoma cell proliferation and glycolysis by partially suppressing PRMT9 and stabilizing HIF-1α protein.

Osteosarcoma (OS) is the most common primary bone tumor, occurring frequently in adolescents and possessing a high malignant severity. MicroRNAs play critical roles during OS development. Thus, elucidation of the involvement of specific microRNAs in the development of OS may provide novel therapeutic targets for OS treatment. Here, we showed that in the OS specimens from patients, the levels of miR-543 were significantly increased whereas the levels of PRMT9 were significantly decreased, compared to the paired normal bone tissue. Moreover, miR-543 and PRMT9 inversely correlated in the OS cell lines. Bioinformatics analyses predicted that miR-543 may target the 3'-UTR of PRMT9 mRNA to inhibit its translation, which was confirmed by luciferase-reporter assay. MiR-543 promoted OS cell proliferation in vitro and in vivo. Mechanistically, miR-543 inhibited PRMT9-enhanced cell oxidative phosphorylation, while miR-543 depletion promoted PRMT9-increased HIF-1α instability and inhibited glycolysis in OS cells. Clinically, miR-543 expression was negatively correlated with PRMT9 expression in OS tissues. Together, our data provide important evidence for glycolysis in OS development, and suggest that targeting glycolytic pathway through miR-543/PRMT9/HIF-1α axis may represent a potential therapeutic strategy to eradicate OS cells.