Bleomycin (BLM) is a natural product with established anticancer activity, attributed to its ability to cleave intracellular DNA. BLM complexes with iron (BLM-Fe) exhibit peroxidase-like activity, generate reactive oxygen species (ROS), and cause DNA cleavage. Inspired by the mechanism of BLM, we synthesized a novel conjugate of manganese tetraphenylporphyrin (MnTPP) with a biomimetic peptoid (i.
View Article and Find Full Text PDFAdverse effects of spaceflight on the human body are attritubuted to microgravity and space radiation. One of the most sensitive organs affected by them is the eye, particularly the retina. The conditions that astronauts suffer, such as visual acuity, is collectively called a spaceflight-associated neuro-ocular syndrome (SANS); however, the underlying molecular mechanism of the microgravity-induced ocular pathogenesis is not clearly understood.
View Article and Find Full Text PDFBy utilizing a multimodal nonlinear optical system that combines coherent anti-Stokes Raman scattering and second harmonic generation to investigate biological characteristics of dermal tissues ex vivo, we demonstrate the potential feasibility of using this optical approach as a powerful new investigative tool for future biomedical research. For this study, our optical system was utilized for the first time to analyze lipid and collagen profiles in cereblon knockout (KO) mouse skin, and we were able to discover significant alterations in the number of carbon-carbon double bonds (wild-type vs. cereblon KO; N : 0.
View Article and Find Full Text PDFIn this study, we designed photo-triggered reactive oxygen species (ROS)-generating pheophorbide A and ROS-cleavable thioketal-SN38 conjugated hyaluronan-cholesterol nanoparticles (PheoA-SN38-HC NPs). And we observed the combined therapeutic effects of PheoA-SN38-HC NPs against HEY-T30 human ovarian cancer (OC) model. Clinical Proteomic Tumor Analysis Consortium (CPTAC) data showed that the expression of cancer stem cell (CSC) markers (CD44, ALDH1A1, and CD117) is highly associated with poor clinical outcomes in OC patients.
View Article and Find Full Text PDFCereblon (CRBN) is a substrate receptor of the cullin-RING E3 ubiquitin ligase (CRL) complex that mediates the ubiquitination of several substrates. In this study, CRBN knockout (KO) mice exhibited decreased levels of stratum corneum hydration (SCH) and collagen I expression with an elevated protein level of matrix metalloprotease 1 (MMP1). The absence of cereblon in the skin of CRBN KO mice mimics the damage caused by narrowband ultraviolet B (NB-UVB).
View Article and Find Full Text PDFCalcium flux regulating intracellular calcium levels is essential and modulated for efficient efferocytosis. However, the molecular mechanism by which calcium flux is modulated during efferocytosis remains elusive. Here, we report that Orai1, a Crbn substrate, is upregulated via its attenuated interaction with Crbn during efferocytosis, which increases calcium influx into phagocytes and thereby promotes efferocytosis.
View Article and Find Full Text PDFCan J Gastroenterol Hepatol
August 2019
Background: Hepatocellular carcinoma (HCC) is one of the most common malignant cancers with a poor prognosis. Several commonly investigated immunohistochemical markers in resected HCC have potential prognostic value, but the prognostic utility of p53 expression in HCC has remained elusive.
Aim: To evaluate the prognostic value of p53 and p53 phosphorylation at serine 15 (p53 Ser15-P) in patients with HCC.
Hepatic fibrosis is characterized by the excessive accumulation of extracellular matrix (ECM), primarily collagen, within the liver. Because reactive oxygen species (ROS) has been implicated in its pathogenesis, the use of antioxidants as a potential treatment has been broadly explored. Here, we investigated the hepatoprotective properties of ramalin (RM), a compound extracted from the Antarctic lichen Ramalina terebrata, against hepatic fibrosis in vitro and in vivo.
View Article and Find Full Text PDFScreening a compound library of quinolinone derivatives identified compound 11a as a new P2X7 receptor antagonist. To optimize its activity, we assessed structure-activity relationships (SAR) at three different positions, R, R and R, of the quinolinone scaffold. SAR analysis suggested that a carboxylic acid ethyl ester group at the R position, an adamantyl carboxamide group at R and a 4-methoxy substitution at the R position are the best substituents for the antagonism of P2X7R activity.
View Article and Find Full Text PDFMitochondria-specific delivery methods offer a valuable tool for studying mitochondria-related diseases and provide breakthroughs in therapeutic development. Although several small-molecule and peptide-based transporters have been developed, peptoids, proteolysis-resistant peptidomimetics, are a promising alternative to current approaches. We designed a series of amphipathic peptoids and evaluated their cellular uptake and mitochondrial localization.
View Article and Find Full Text PDFMyeloid-derived suppressor cells (MDSCs) regulate T cell immunity, and this population is a new therapeutic target for immune regulation. A previous study showed that transforming growth factor-β (TGF-β) is involved in controlling MDSC differentiation and immunoregulatory function in vivo. However, the direct effect of TGF-β on MDSCs with various cytokines has not previously been tested.
View Article and Find Full Text PDFPDK1 is essential for T cell receptor (TCR)-mediated activation of NF-κB, and PDK1-induced phosphorylation of PKCθ is important for TCR-induced NF-κB activation. However, inverse regulation of PDK1 by PKCθ during T cell activation has not been investigated. In this study, we found that PKCθ is involved in human PDK1 phosphorylation and that its kinase activity is crucial for human PDK1 phosphorylation.
View Article and Find Full Text PDFEfforts to identify and target glioblastoma (GBM) drivers have primarily focused on receptor tyrosine kinases (RTKs). Clinical benefits, however, have been elusive. Here, we identify an SRY-related box 2 (SOX2) transcriptional regulatory network that is independent of upstream RTKs and capable of driving glioma-initiating cells.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
April 2016
In this study, we prepared macromolecular MR T1 contrast agent: pullulan-conjugated Gd diethylene triamine pentaacetate (Gd-DTPA-Pullulan) and estimated residual free Gd(3+), chelation stability in competition with metal ions, plasma and tissue pharmacokinetics, and abdominal MR contrast on rats. Residual free Gd(3+) in Gd-DTPA-Pullulan was measured using colorimetric spectroscopy. The transmetalation of Gd(3+) incubated with Ca(2+) was performed by using a dialysis membrane (MWCO 100-500 Da) and investigated by ICP-OES.
View Article and Find Full Text PDFIt has been hypothesized that increased flux through the pentose phosphate pathway (PPP) is required to support the metabolic demands of rapid malignant cell growth. Using orthotopic mouse models of human glioblastoma (GBM) and renal cell carcinoma metastatic to brain, we estimated the activity of the PPP relative to glycolysis by infusing [1,2-(13) C(2) ]glucose. The [3-(13) C]lactate/[2,3-(13) C(2) ]lactate ratio was similar for both the GBM and brain metastasis and their respective surrounding brains (GBM, 0.
View Article and Find Full Text PDFExposing rare but highly malignant tumor cells that migrate from the primary tumor mass into adjacent tissue(s) or circulate in the bloodstream is critical for early detection and effective intervention(s). Here, we report on an aptamer-based strategy directed against epidermal growth factor receptor (EGFR), the most common oncogene in glioblastoma (GBM), to detect these deadly tumor cells. GBMs are characterized by diffuse infiltration into normal brain regions, and the inability to detect GBM cells renders the disease surgically incurable with a median survival of just 14.
View Article and Find Full Text PDFThe neuronal ceroid lipofuscinoses (NCLs, also known collectively as Batten disease) are a group of lysosomal storage disorders characterized by the accumulation of autofluorescent storage material in the brain and other tissues. A number of genes underlying various forms of NCL have been cloned, but the basis for the neurodegeneration in any of these is unknown. High levels of dolichol pyrophosphoryl oligosaccharides have previously been demonstrated in brain tissue from several NCL patients, but the specificity of the effect for the NCLs has been unclear.
View Article and Find Full Text PDFInfantile Batten disease is a severe neurodegenerative storage disorder caused by mutations in the human PPT1 (palmitoyl protein thioesterase 1) gene, which encodes a lysosomal hydrolase that removes fatty acids from lipid-modified proteins. PPT1 has orthologs in many species, including lower organisms and plants, but not in Saccharomyces cerevisiae. The fission yeast Schizosaccharomyces pombe contains a previously uncharacterized open reading frame (SPBC530.
View Article and Find Full Text PDFThe CWH8 gene in Saccharomyces cerevisiae has been shown recently (Fernandez, F., Rush, J. S.
View Article and Find Full Text PDFInfantile and classical late infantile neuronal ceroid lipofuscinoses (NCL) are two recent additions to the expanding spectrum of lysosomal storage disorders caused by deficiencies in lysosomal hydrolases. They are latecomers to the lysosomal storage disorders, probably because of the heterogeneous nature of the storage material, which precluded meaningful biochemical analysis. Infantile NCL is caused by deficiency in palmitoyl-protein thioesterase, an enzyme that hydrolyzes fatty acids from cysteine residues in lipid-modified proteins.
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