Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The microenvironment of the intervertebral disc (IVD) is characterized by matrix acidity, hypoxia, hyperosmolarity and limited nutrition, which are major obstacles to stem cell-based regeneration. Our recent work showed that nucleus pulposus mesenchymal stem cells (NPMSCs) had advantages over traditional sources of cell therapy under IVD-like hypoxic and hyperosmotic conditions. Here, we examined the viability, proliferation and matrix metabolism of NPMSCs compared with adipose tissue-derived mesenchymal stem cells (ADMSCs) under IVD-like acidic conditions in vitro. ADMSCs and NPMSCs from Sprague-Dawley rats were cultured at four different pH levels representing the standard condition (pH 7.4) and the normal, mildly degenerated and severely degenerated IVD (pH 7.1, 6.8 and 6.5, respectively). Cell viability was examined by annexin-V-fluorescein isothiocyanate/propidium iodide staining. Cell proliferation was measured using a cell counting kit cell proliferation assay. The expression of aggrecan, collagen-I, collagen-II, matrix metalloproteinase-2 (MMP-2), a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS4) and the tissue inhibitor of metalloproteinase-3 (TIMP-3) was measured at mRNA and protein levels by RT-PCR and Western blotting. In both cell types, acidic pH inhibited cell viability and proliferation, downregulated the expression of aggrecan, collagen-I, collagen-II and TIMP-3, and upregulated the expression of MMP-2 and ADAMTS4. Compared with ADMSCs, NPMSCs were significantly less inhibited in viability and proliferation; they expressed significantly higher levels of aggrecan and collagen-II, and lower levels of MMP-2 and ADAMTS4. Thus, an acidic environment is a major obstacle for IVD regeneration by ADMSCs or NPMSCs. NPMSCs appeared less sensitive to inhibition by acidic pH and might be promising candidates for cell-based IVD regeneration.
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PMID:Nucleus pulposus mesenchymal stem cells in acidic conditions mimicking degenerative intervertebral discs give better performance than adipose tissue-derived mesenchymal stem cells. 2566 84

Prodrug self-assembled nanomedicines with cleavable moieties sensitive to intracellular stimuli have attracted great interest to pharmacists. In this paper, a docetaxel-hyaluronic acid (DTX-HA) conjugate with peptide, hydrazone bonds and disulfide in sequence, which were cleavable catalyzed by metalloproteinase (MMP), weak acidity and glutathione (GSH), respectively, were involved in a moiety as the linker to immobilize DTX on HA chains, the prodrugs were self-assembled into nanoparticles and utilized for cancer chemotherapy. The synthesis of conjugate was characterized by 1H NMR, ESI-TOF and GPC. The self-assembly of the conjugates was investigated via DLS and TEM. The release profiles revealed that the nanomedicine was disassociated to trigger the drug release in the simulated intracellular conditions of MMP, pH value and GSH, respectively. The in vitro anticancer activity of the nanomedicine with IC50 test, cytometry and confocal laser scanning microscopy exhibited efficient cellular uptake and apoptosis of cancer cells. The in vivo anticancer study of the nanomedicine in tumor-bearing nude mice showed promising therapeutic efficacy in magnificent inhibition tumor growth, long circulation time in pharmacokinetic and low toxicity to organs.
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PMID:Integrated Metalloproteinase, pH and Glutathione Responsive Prodrug-Based Nanomedicine for Efficient Target Chemotherapy. 3121 20

The rapid development of treatment resistance in tumors poses a technological bottleneck in clinical oncology. Ferroptosis is a form of regulated cell death with clinical translational potential, but the efficacy of ferroptosis-inducing agents is susceptible to many endogenous factors when administered alone, for which some cooperating mechanisms are urgently required. Here, we report an amorphous calcium carbonate (ACC)-based nanoassembly for tumor-targeted ferroptosis therapy, in which the totally degradable ACC substrate could synergize with the therapeutic interaction between doxorubicin (DOX) and Fe2+. The nanoplatform was simultaneously modified by dendrimers with metalloproteinase-2 (MMP-2)-sheddable PEG or targeting ligands, which offers the functional balance between circulation longevity and tumor-specific uptake. The therapeutic cargo could be released intracellularly in a self-regulated manner through acidity-triggered degradation of ACC, where DOX could amplify the ferroptosis effects of Fe2+ by producing H2O2. This nanoformulation has demonstrated potent ferroptosis efficacy and may offer clinical promise.
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PMID:Tumor microenvironment-activatable Fe-doxorubicin preloaded amorphous CaCO3 nanoformulation triggers ferroptosis in target tumor cells. 3249 59