RESUMEN
Morphine is a frequently used analgesic that activates the mu-opioid receptor(MOR),which has prominent side effects of tolerance.Although the inefficiency of morphine in inducing the endocytosis of MOR underlies the development of morphine tolerance,currently,there is no effective therapy to treat morphine tolerance.In the current study,we aimed to develop a monoclonal antibody(mAb)precisely targeting MOR and to determine its therapeutic efficacy on morphine tolerance and the underlying molecular mechanisms.We successfully prepared a mAb targeting MOR,named 3A5C7,by hybridoma technique using a strategy of deoxyribonucleic acid immunization combined with cell immunization,and identified it as an immunoglobulin G mAb with high specificity and affinity for MOR and binding ability to antigens with spatial conformation.Treatment of two cell lines,HEK293T and SH-SY5Y,with 3A5C7 enhanced morphine-induced MOR endocytosis via a G protein-coupled receptor kinase 2(GRK2)/β-arrestin2-dependent mechanism,as demonstrated by immunofluorescence staining,flow cytometry,Western blotting,coimmunoprecipitation,and small interfering ribonucleic acid(siRNA)-based knock-down.This mAb also allowed MOR recycling from cytoplasm to plasma membrane and attenuated morphine-induced phosphorylation of MOR.We established an in vitro morphine tolerance model using differentiated SH-SY5Y cells induced by retinoic acid.Western blot,enzyme-linked immunosorbent assays,and siRNA-based knockdown revealed that 3A5C7 mAb diminished hyperactivation of adenylate cyclase,the in vitro biomarker of morphine tolerance,via the GRK2/β-arrestin2 pathway.Furthermore,in vivo hotplate test demonstrated that chronic intrathecal administration of 3A5C7 significantly alle-viated morphine tolerance in mice,and withdrawal jumping test revealed that both chronic and acute 3A5C7 intrathecal administration attenuated morphine dependence.Finally,intrathecal electroporation of silencing short hairpin RNA illustrated that the in vivo anti-tolerance and anti-dependence efficacy of 3A5C7 was mediated by enhanced morphine-induced MOR endocytosis via GRK2/β-arrestin2 pathway.Collectively,our study provided a therapeutic mAb,3A5C7,targeting MOR to treat morphine tolerance,mediated by enhancing morphine-induced MOR endocytosis.The mAb 3A5C7 demonstrates promising translational value to treat clinical morphine tolerance.
RESUMEN
OBJECTIVE@#Cancer is a serious threat to human health. Despite extensive research on cancer treatment, there is a growing demand for new therapies. CD147 is widely involved in tumor development, but it is unclear whether cancer cell malignancy is affected by CD147 expression level. The first compound (AC-73) targeting CD147 could only act on advanced tumors and inhibit metastasis. Therefore, new compounds with better anticancer activity should be explored.@*METHODS@#Wst-1 assays were used to confirm the effect of novel compounds on proliferation. Apoptosis tests were used to evaluate their proapoptotic capacity. A nude mouse model was used to demonstrate in vivo anticancer activity and safety of the compounds. Western blots were used to suggest a molecule mechanism.@*RESULTS@#There is a positive correlation between CD147 expression and tumor cell proliferation. A new compound, HA-08, was synthesized and proved to be more active than AC-73. HA-08 could inhibit cancer cell viability and promote cancer cell apoptosis both in vitro and in vivo. HA-08 induces cancer apoptosis, mainly by disrupting the CD147-CD44 interaction and then down-regulating the JAK/STAT3/Bcl-2 signaling pathway.@*CONCLUSION@#Our results have clarified the tumor specificity of CD147 and its drug target characteristics. The biological profile of HA-08 suggests that this compound could be developed as a potential anticancer agent.
RESUMEN
CD147 (basigin, EMMPRIN, neurothelin, M6, HAb18G, etc.), a transmembrane glycoprotein, has a broad expression pattern on various epithelial cells with some differences between species, e.g. rat, mouse, chicken and human, but is highly enriched on the surface of cancer cells of epithelial origin such as lung cancer, breast cancer and hepatoma cells. The CD147 antigen consists of two IgSF domains, a transmembrane sequence containing a charged residue (Glu) and a cytoplasmic domain of 40 residues. The particular structural features suggest that it is involved in protein-protein interactions. Although the interacting molecules are still not well known due to unavailability of the 3D structure of CD147, adhesion, coimmunoprecipitation and other studies recently suggest that several proteins, including integrins, cyclophilins, MCT, etc., interact with CD147 as its ligand or receptor candidates to mediate a wide range of cellular functions.
Asunto(s)
Animales , Humanos , Ratones , Ratas , Basigina , Fisiología , Pollos , Conformación ProteicaRESUMEN
?ig-h_3 was first identified as a transforming growth factor-beta1-inducible gene in human lung adenocarcinoma cell line. It encodes for a secreted extracellular matrix (ECM) protein, which is thought to act on cell attachment and ECM composition. Previous study showed that ?ig-h_3 were highly expressed in human hepatoma cell lines and lowly expressed in human normal hepatic cells. The present study aimed to transfect ?ig-h_3 into 7721 cells to investigate its effect on secretion of MMPs in the transfected human hepatoma cells. Full-length ?ig-h_3 gene,cloned by reverse transcription polymerase chain reaction (RT-PCR) was inserted into the eukaryotic expression vector pEGFP-C_2. The recombinant plasmid was transfected into 7721 cells with Lipofectamine2000 and Gelatin-Zymography were adopted to detect the production of MMPs in the transfected cells. Results showed that ?ig-h_3/pEGFP-C_2 recombinant expression plasmid was successfully constructed and achieved high transfection efficiency. MMPs expression of the transfected cells was promoted significantly. These results suggest that overexpression of ?ig-h_3 promoted the production of MMPs, indicating that ?ig-h_3 may play roles in the invasive and metastatic processes of hepatoma.
RESUMEN
<p><b>OBJECTIVE</b>To investigate the effect of Ca(2+) mobilization on release and activation of matrix metalloproteinases (MMPs) in human hepatocellular carcinoma cells.</p><p><b>METHODS</b>Ca(2+) and chemicals which can induce or inhibit Ca(2+) mobilization were added into human SMMC-7721 hepatoma cells in vitro. SDS-PAGE protein electrophoresis and gelatin zymography analysis were carried out to detect the changes of release and activation of MMPs in the cell culture supernatant.</p><p><b>RESULTS</b>Addition of CaCl(2) into culture system resulted in an enhanced secretion and activation of MMP-2 and MMP-9 in a dose-dependent manner. At a dose of 0.8 mmol/L CaCl(2), it maintained a stable high level of MMPs, especially of MMP-2 with (109.71 +/- 27.93)% elevation as compared to the cells without CaCl(2) addition (P < 0.001). SDS-PAGE analysis showed that most secreted proteins were MMPs (MMP-2 and MMP-9) when the cells cultured in media without serum. Thapsigargin (Tg, 4 micromol/L), an inducer of intracellular Ca(2+) stores depletion, significantly enhanced the release and activation of MMP-2 and MMP-9, compared to the control with (58.63 +/- 31.04)% elevation (P < 0.05), while the inducing effect of Tg on MMPs release and activation was significantly inhibited by S-nitro-N-acetylpenicillamine (SNAP, 200 micromol/L), an NO donor.</p><p><b>CONCLUSION</b>Intracellular Ca(2+) regulation pathways may play an important role in the process of release and activation of MMPs.</p>