ABSTRACT
Exosomes derived from human bone marrow mesenchymal stem cells (MSC-Exo) are characterized by easy expansion and storage, low risk of tumor formation, low immunogenicity, and anti-inflammatory effects. The therapeutic effects of MSC-Exo on ischemic stroke have been widely explored. However, the underlying mechanism remains unclear. In this study, we established a mouse model of ischemic brain injury induced by occlusion of the middle cerebral artery using the thread bolt method and injected MSC-Exo into the tail vein. We found that administration of MSC-Exo reduced the volume of cerebral infarction in the ischemic brain injury mouse model, increased the levels of interleukin-33 (IL-33) and suppression of tumorigenicity 2 receptor (ST2) in the penumbra of cerebral infarction, and improved neurological function. In vitro results showed that astrocyte-conditioned medium of cells deprived of both oxygen and glucose, to simulate ischemia conditions, combined with MSC-Exo increased the survival rate of primary cortical neurons. However, after transfection by IL-33 siRNA or ST2 siRNA, the survival rate of primary cortical neurons was markedly decreased. These results indicated that MSC-Exo inhibited neuronal death induced by oxygen and glucose deprivation through the IL-33/ST2 signaling pathway in astrocytes. These findings suggest that MSC-Exo may reduce ischemia-induced brain injury through regulating the IL-33/ST2 signaling pathway. Therefore, MSC-Exo may be a potential therapeutic method for ischemic stroke.
ABSTRACT
BACKGROUND: Cardiogenic shock continues to be a highly morbid complication that affects around 7%-10% of patients with acute myocardial infarction or heart failure. Similarly, obesity has become a worldwide epidemic. AIM: To analyze the impact of higher body mass index (BMI) on outcomes of patients with cardiogenic shock. METHODS: A systematic and comprehensive search was undertaken on the electronic databases of PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar for all types of studies comparing mortality outcomes of patients with cardiogenic shock based on BMI. All studies defined overweight or obese patients based on the World Health Organization BMI criteria. The data were then extracted and assessed on the basis of the Reference Citation Analysis (https://www.referencecitationanalysis.com/). RESULTS: Five studies were included. On pooled analysis of multivariable-adjusted ratios, we noted a statistically significantly reduced risk of mortality in overweight/obese vs normal patients (three studies; odds ratio [OR] = 0.92, 95% confidence interval [CI]: 0.85-0.98, I 2 = 85%). On meta-analysis, we noted that crude mortality rates did not significantly differ between overweight/obese and normal patients after cardiogenic shock (OR = 0.95, 95%CI: 0.79-1.15, I 2 = 99%). The results were not stable on sensitivity analysis and were associated with substantial heterogeneity. CONCLUSION: Current evidence on the association between overweight/obesity and mortality after cardiogenic shock is scarce and conflicting. The obesity paradox might exist in patients with cardiogenic shock but could be confounded by the use of mechanical circulatory support. There is a need for further studies to clarify this relationship.
ABSTRACT
5-FU is a common first-line chemotherapeutic drug for the treatment of hepatocellular carcinoma. However the development of acquired resistance to 5-FU confines its clinical usages. Although this phenomenon has been the subject of intense investigation, the exact mechanism of acquired resistance to 5-FU remains elusive. Here, we report that over-expression of GRP78 contributes to acquired resistance to 5-FU in HCC by up-regulating the c-Src/LSF/TS axis. Moreover, we found that the resistance to 5-FU conferred by GRP78 is mediated by its ATPase domain. The ATPase domain differentially increased the expression of LSF, TS and promoted the phosphorylation of ERK and Akt. We further identified that GRP78 interacts physically with c-Src through its ATPase domain and promotes the phosphorylation of c-Src, which in turn increases the expression of LSF in the nucleus. Together, GRP78 confers the resistance to 5-FU by up-regulating the c-Src/LSF/TS axis via its ATPase domain.
Subject(s)
Carcinoma, Hepatocellular/drug therapy , DNA-Binding Proteins/metabolism , Fluorouracil/pharmacology , Heat-Shock Proteins/metabolism , Liver Neoplasms/drug therapy , Thymidylate Synthase/metabolism , Transcription Factors/metabolism , src-Family Kinases/metabolism , Animals , Antimetabolites, Antineoplastic/pharmacology , CSK Tyrosine-Protein Kinase , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Drug Resistance, Neoplasm , Endoplasmic Reticulum Chaperone BiP , Female , Heat-Shock Proteins/genetics , Hep G2 Cells , Humans , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Middle Aged , Signal Transduction , Thymidylate Synthase/genetics , Xenograft Model Antitumor Assays , src-Family Kinases/geneticsABSTRACT
Invasion is a major characteristic of hepatocellular carcinoma and one of the main causes of refractory to treatment. We have previously reported that GRP78 promotes the invasion of hepatocellular carcinoma although the mechanism underlying this change remains uncertain. In this paper, we explored the role of the cell surface GRP78 in the regulation of cancer cell invasion in hepatocellular carcinoma cells. We found that neutralization of the endogenous cell surface GRP78 with the anti-GRP78 antibody inhibited the adhesion and invasion in hepatocellular carcinoma cell lines Mahlavu and SMMC7721. However, forced expression of the cell surface GRP78 facilitated the adhesion and invasion in SMMC7721. We further demonstrated that inhibition of the endogenous cell surface GRP78 specifically inhibited the secretion and activity of MMP-2 but did not affect the secretion and activity of MMP-9. We also found that inhibition of the cell surface GRP78 increased E-Cadherin expression and decreased N-Cadherin level. On the contrary, forced expression of the cell surface GRP78 increased N-Cadherin expression and decreased E-Cadherin level, suggesting that the cell surface GRP78 plays critical role in the regulation of EMT process. These findings suggest that the cell surface GRP78 plays a stimulatory role in the invasion process and may be a potential anti-invasion target for the treatment of hepatocellular carcinoma.
Subject(s)
Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/physiopathology , Heat-Shock Proteins/physiology , Liver Neoplasms/pathology , Liver Neoplasms/physiopathology , Antigens, CD/metabolism , Cadherins/metabolism , Cell Adhesion/physiology , Cell Line, Tumor , Cell Membrane/physiology , Endoplasmic Reticulum Chaperone BiP , Epithelial-Mesenchymal Transition/physiology , Heat-Shock Proteins/antagonists & inhibitors , Humans , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Neoplasm Invasiveness/pathology , Neoplasm Invasiveness/physiopathology , Neoplasm Proteins/physiologyABSTRACT
AIM: To construct a recombinant plasmid pGEX-4T-1-GRP78, express it and purify human glucose regulated protein 78 (GRP78). METHODS: GRP78 gene was amplified by PCR from the recombinant vector constructed in our laboratory. The PCR product was inserted into pGEX-4T-1 prokaryotic expression vector to generate pGEX-4T-1-GRP78. The pGEX-4T-1-GRP78 was then transformed into BL21 and GRP78 was expressed on induction of IPTG. After purification, GRP78 was released by thrombin cleavage, and its antigenicity was identified by ELISA. RESULTS: The GRP78 prokaryotic expression vector was successfully constructed as confirmed by enzyme digestion and DNA sequencing. ELISA demonstrated the antigenicity of the purified GRP78 protein. CONCLUSION: The recombinant prokaryotic expression vector pGEX-4T-1-GRP78 has been constructed successfully. The purified GRP78 has been obtained with good antigenicity, which will be used for GRP78-based serum diagnosis of hepatocellular carcinoma.
