Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), one of the most common maternally inherited mitochondrial diseases, is caused by mitochondrial DNA mutations that ...lead to mitochondrial dysfunction. Several treatment options exist, including supplementation with CoQ10, vitamins, and nutrients, but no treatment with proven efficacy is currently available. In this study, we investigated the effects of a novel NAD
modulator, KL1333, in human fibroblasts derived from a human patient with MELAS. KL1333 is an orally available, small organic molecule that reacts with NAD(P)H:quinone oxidoreductase 1 (NQO1) as a substrate, resulting in increases in intracellular NAD
levels via NADH oxidation. To elucidate the mechanism of action of KL1333, we used C2C12 myoblasts, L6 myoblasts, and MELAS fibroblasts. Elevated NAD
levels induced by KL1333 triggered the activation of SIRT1 and AMPK, and subsequently activated PGC-1α in these cells. In MELAS fibroblasts, KL1333 increased ATP levels and decreased lactate and ROS levels, which are often dysregulated in this disease. In addition, mitochondrial functional analyses revealed that KL1333 increased mitochondrial mass, membrane potential, and oxidative capacity. These results indicate that KL1333 improves mitochondrial biogenesis and function, and thus represents a promising therapeutic agent for the treatment of MELAS.
Transforming growth factor‐beta (TGFβ) is an enigmatic protein with various roles in healthy tissue homeostasis/development as well as the development or progression of cancer, wound healing, ...fibrotic disorders, and immune modulation, to name a few. As TGFβ is causal to various fibroproliferative disorders featuring localized or systemic tissue/organ fibrosis as well as the activated stroma observed in various malignancies, characterizing the pathways and players mediating its action is fundamental. In the current study, we found that TGFβ induces the expression of the immunoinhibitory molecule Programed death‐ligand 1 (PD‐L1) in human and murine fibroblasts in a Smad2/3‐ and YAP/TAZ‐dependent manner. Furthermore, PD‐L1 knockdown decreased the TGFβ‐dependent induction of extracellular matrix proteins, including collagen Iα1 (colIα1) and alpha‐smooth muscle actin (α‐SMA), and cell migration/wound healing. In addition to an endogenous role for PD‐L1 in profibrotic TGFβ signaling, TGFβ stimulated‐human lung fibroblast‐derived PD‐L1 into extracellular vesicles (EVs) capable of inhibiting T cell proliferation in response to T cell receptor stimulation and mediating fibroblast cell migration. These findings provide new insights and potential targets for a variety of fibrotic and malignant diseases.
Bisphenol A (BPA) is a high-volume industrial chemical used in the global production of polycarbonate plastics and epoxy resins, which are used in food and drink containers, such as tableware (plates ...and mugs). Due to its broad applications, BPA has been detected in human blood, urine and breast milk as well as environmental substances, including water, indoor and outdoor air, and dust. Indeed, exposure to high concentrations of BPA can result in a variety of harmful effects, including reproductive toxicity, through a mechanism of endocrine disruption. Our comparison of reported BPA urinary concentrations among different countries revealed that exposures in Korea may be higher than those in other Asian countries and North America, but lower than or similar to those in European countries. The current study included a total of 2044 eligible subjects of all ages. The subjects were evenly divided between males and females (48.58% and 51.42%, respectively). The geometric mean (GM) of pre-adjusted (adjusted) urinary BPA concentrations was 1.83μg/L (2.01μg/g creatinine) for subjects of all ages, and there was no statistically difference in BPA concentrations between males (1.90μg/L, 1.87μg/g creatinine) and females (1.76μg/L, 2.16μg/g creatinine). Multiple regression analysis revealed only one positive association between creatinine pre-adjusted urinary BPA concentration and age (β=−0.0868, p<0.001). The 95th percentile levels of 24-hour recall (HR), food frequency questionnaires (FFQ) and estimated daily intake (EDI) through urinary BPA concentrations were 0.14, 0.13, and 0.22μg/kg bw/day, respectively. According to the Ministry of Food and Drug Safety (MFDS), a tolerable daily intake (tDI) of 20μg/kg bw/day was established for BPA from the available toxicological data. Recently, the European Food Safety Authority (EFSA) established a temporary TDI of 4μg/kg bw/day based on current toxicological data. By comparing these TDIs with subjects' exposure, we conclude that there are no health concerns for any age group as a result of current levels of dietary exposure to BPA.
•We compared urinary bisphenol A (BPA) levels among different countries.•We evaluated the urinary BPA levels of the general Korean population.•We found that the overall GM of urinary BPA concentration was 1.83μg/L.•We derived a TDI of 20μg/kg bw/day for BPA.•There is no health concern for any age group from current levels of exposure to BPA.
This study explores the interrelationship between absorptive capacity and knowledge sharing, which are innovation-specific antecedents of innovative behaviour. By differentiating the two ...sub-dimensions of absorptive capacity, potential and realised absorptive capacity, previous contradictory findings on the relationship between absorptive capacity and knowledge sharing are reconciled. To verify the research hypotheses, the survey responses from 138 R&D employees of a multinational electronics company are analysed through structural equation modelling. The results show that both sub-dimensions of absorptive capacity directly influence innovative behaviour. However, knowledge sharing's effect on innovative behaviour is indirect through realised absorptive capacity. The research findings imply employees' absorptive capacity and knowledge sharing among them should be nurtured simultaneously to facilitate innovative behaviour. In addition to providing employees with many opportunities to be exposed to external knowledge, internal communications among employees and exploratory trials exploiting external knowledge along with internal knowledge should be encouraged.
It is essential to characterize the cellular properties of mesenchymal stem cell populations to maintain quality specifications and control in regenerative medicine. Biofunctional materials have been ...designed as artificial matrices for the stimulation of cell adhesion and specific cellular functions. We have developed recombinant maltose‐binding protein (MBP)‐fused proteins as artificial adhesion matrices to control human mesenchymal stem cell (hMSC) fate by using an integrin‐independent heparin sulfate proteoglycans‐mediated cell adhesion. In this study, we characterize cell adhesion‐dependent cellular behaviors of human adipose‐derived stem cells (hASCs) and human bone marrow stem cells (hBMSCs). We used an MBP‐fused basic fibroblast growth factor (MF)‐coated surface and fibronectin (FN)‐coated surface to restrict and support, respectively, integrin‐mediated adhesion. The cells adhered to MF exhibited restricted actin cytoskeleton organization and focal adhesion kinase phosphorylation. The hASCs and hBMSCs exhibited different cytoplasmic projection morphologies on MF. Both hASCs and hBMSCs differentiated more dominantly into osteogenic cells on FN than on MF. In contrast, hASCs differentiated more dominantly into adipogenic cells on MF than on FN, whereas hBMSCs differentiated predominantly into adipogenic cells on FN. The results indicate that hASCs exhibit a competitive differentiation potential (osteogenesis vs. adipogenesis) that depends on the cell adhesion matrix, whereas hBMSCs exhibit both adipogenesis and osteogenesis in integrin‐mediated adhesion and thus hBMSCs have noncompetitive differentiation potential. We suggest that comparing differentiation behaviors of hMSCs with the diversity of cell adhesion is an important way to characterize hMSCs for regenerative medicine.
A recombinant protein was designed to generate a novel cell adhesion mechanism. We found marked differences between human adipose‐derived stem cells and human bone marrow stem cells in cellular behavior and differentiation, depending on the cell adhesion mechanism.
DNA damage‐induced apoptosis suppressor (DDIAS) facilitates the survival of lung cancer by suppressing apoptosis. Moreover, DDIAS promotes tyrosine phosphorylation of signal transducer and activator ...of transcription 3 (STAT3) via their interaction. Here, we identified miconazole as an inhibitor of DDIAS/STAT3 interaction by screening a chemical library using a yeast two‐hybrid assay. Miconazole inhibited growth, migration and invasion of lung cancer cells. Furthermore, miconazole suppressed STAT3 tyrosine Y705 phosphorylation and the expression of its target genes, such as cyclin D1, survivin and snail but had no suppressive effect on the activation of ERK1/2 or AKT, which is involved in the survival of lung cancer. As expected, no interaction between DDIAS and STAT3 occurred in the presence of miconazole, as confirmed by immunoprecipitation assays. Mouse xenograft experiments showed that miconazole significantly suppressed both tumor size and weight in an NCI‐H1703 mouse model. Tyrosine phosphorylation of STAT3 at Y705 and expression of its targets, such as cyclin D1, survivin and snail, were decreased in miconazole‐treated tumor tissues, as compared with those in vehicle‐treated tumor tissues. These data suggest that miconazole exerts an anti–cancer effect by suppressing STAT3 activation through inhibiting DDIAS/STAT3 binding.
DNA damage‐induced apoptosis suppressor promotes activation of tyrosine phosphorylation of STAT3 through their interaction. Miconazole exerts an anti–cancer effect by suppressing STAT3 activation through inhibition of DDIAS/STAT3 binding.
Naegleria fowleri is a ubiquitous protozoa parasite that can cause primary amoebic meningoencephalitis (PAM), a fatal brain infection in humans. Cathepsin Bs of N. fowleri (NfCBs) are multifamily ...enzymes. Although their pathogenic mechanism in PAM is not clearly understood yet, NfCBs have been proposed as pathogenic factors involved in the pathogenicity of amoeba. In this study, the immune response of BV-2 microglial cells induced by NfCB was analyzed. Recombinant NfCB (rNfCB) evoked enhanced expressions of TLR-2, TLR-4, and MyD88 in BV-2 microglial cells. This enzyme also induced an elevated production of several pro-inflammatory cytokines such as TNF-α, IL-1α, IL-1β, and IL-6 and iNOS in cells. The inhibition of mitogen-activated protein kinases (MAPKs), including JNK, p38, and ERK, effectively reduced the production of these pro-inflammatory cytokines. The rNfCB-induced production of pro-inflammatory cytokines in BV-2 microglial cells was suppressed by inhibiting NF-kB and AP-1. Phosphorylation and nuclear translocation of p65 in cells were also enhanced by rNfCB. These results suggest that NfCB can induce a pro-inflammatory immune response in BV-2 microglial cells via the NF-κB- and AP-1-dependent MAPK signaling pathways. Such a NfCB-induced pro-inflammatory immune response in BV-2 microglial cells might contribute to the pathogenesis of PAM caused by amoeba, by exacerbating deleterious immune responses and tissue damages in N. fowleri-infected foci of the brain.
To develop clinical predictive nomograms generating per-patient numerical probabilities of postoperative recurrence-free and overall survival at specific times.
The prognosis after surgical resection ...is diverse in patients with early-stage hepatocellular carcinoma (HCC).
In a retrospective review, we evaluated data from 1085 mostly early-stage patients newly diagnosed with HCC who were subsequently treated by curative resection. We randomly divided the subjects into derivation (n = 760) and validation (n = 325) samples. Multivariate Cox proportional hazards models were developed and separately validated on the basis of pre- and postoperative clinical and pathological covariates assessed for association with 2-year recurrence and 5-year HCC-specific death. The discriminatory accuracy of the models was compared with traditional tools by analyzing receiver operating characteristic curves.
The statistical nomograms built on the basis of sex, serum albumin, platelet count, microvascular invasion, and calculated tumor volume had good calibration and discriminatory abilities, with c-indices of 0.69 (2-year recurrence) and 0.66 (5-year survival), respectively. These models showed satisfactory goodness-of-fit and discrimination abilities in the independent validation cohort (c-index, 0.66 for 2-year recurrence; and 0.67 for 5-year survival). The areas under the receiver operating characteristic curve using our methods were greater than those of conventional staging systems in the validation patients, indicating better discriminatory capability (corresponding c-indices, 0.55-0.56; and 0.55-0.61, respectively).
Our simple user-friendly calculators, which present graphically postsurgical prognostic models for recurrence and survival outcomes in patients with curatively resectable HCC, offer useful guidance to clinicians and patients for individually planning recurrence surveillance and adjuvant therapy.
The antitumor activity of fucoidan from Fucus vesiculosus was investigated in human colon carcinoma cells. The crude fucoidan, a polysaccharide composed predominantly of sulfated fucose, markedly ...inhibited the growth of HCT-15 cells (human colon carcinoma cells). After HCT-15 cells were treated with fucoidan, several apoptotic events such as DNA fragmentation, chromatin condensation and increase of the population of sub-G1 hypodiploid cells were observed. In the mechanism of fucoidan-induced apoptosis, we examined changes in Bcl-2 and Bax protein expression levels and activation of caspases. Fucoidan decreased Bcl-2 expression, whereas the expression of Bax was increased in a time-dependent manner compared to the control. In addition, the active forms of caspase-9 and caspase-3 were increased, and the cleavage of poly(ADP-ribose) polymerase (PARP), a vital substrate of effector caspase, was observed. Furthermore, the induction of apoptosis was also accompanied by a strong activation of extracellular signal-regulated kinase (ERK) and p38 kinase and an inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt in a time-dependent manner. These findings provide evidence demonstrating that the pro-apoptotic effect of fucoidan is mediated through the activation of ERK, p38 and the blocking of the PI3K/Akt signal pathway in HCT-15 cells. These data support the hypothesis that fucoidan may have potential in colon cancer treatment.
Background Identifying biomarkers related to the diagnosis and treatment of gastric cancer (GC) has not made significant progress due to the heterogeneity of tumors. Genes involved in histological ...classification and genetic correlation studies are essential to develop an appropriate treatment for GC. Methods In vitro and in vivo lentiviral shRNA library screening was performed. The expression of Synaptotagmin (SYT11) in the tumor tissues of patients with GC was confirmed by performing Immunohistochemistry, and the correlation between the expression level and the patient's survival rate was analyzed. Phospho-kinase array was performed to detect Jun N-terminal kinase (JNK) phosphorylation. SYT11, JNK, and MKK7 complex formation was confirmed by western blot and immunoprecipitation assays. We studied the effects of SYT11 on GC proliferation and metastasis, real-time cell image analysis, adhesion assay, invasion assay, spheroid formation, mouse xenograft assay, and liver metastasis. Results SYT11 is highly expressed in the stem-like molecular subtype of GC in transcriptome analysis of 527 patients with GC. Moreover, SYT11 is a potential prognostic biomarker for histologically classified diffuse-type GC. SYT11 functions as a scaffold protein, binding both MKK7 and JNK1 signaling molecules that play a role in JNK1 phosphorylation. In turn, JNK activation leads to a signaling cascade resulting in cJun activation and expression of downstream genes angiopoietin-like 2 (ANGPTL2), thrombospondin 4 (THBS4), Vimentin, and junctional adhesion molecule 3 (JAM3), which play a role in epithelial-mesenchymal transition (EMT). SNU484 cells infected with SYT11 shRNA (shSYT11) exhibited reduced spheroid formation, mouse tumor formation, and liver metastasis, suggesting a pro-oncogenic role of SYT11. Furthermore, SYT11-antisense oligonucleotide (ASO) displayed antitumor activity in our mouse xenograft model and was conferred an anti-proliferative effect in SNU484 and MKN1 cells. Conclusion SYT11 could be a potential therapeutic target as well as a prognostic biomarker in patients with diffuse-type GC, and SYT11-ASO could be used in therapeutic agent development for stem-like molecular subtype diffuse GC. Keywords: GC, SYT11, Metastasis, Stem-like subtype, JNK
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