Cyclooxygenase (COX-1 and COX-2)- and 5-lipoxygenase (5-LOX)-catalyzed biosynthesis of eicosanoids play important roles in inflammation and chronic diseases. The vitamin E family has four tocopherols ...and tocotrienols. We have shown that the metabolites of δ-tocopherol (δT) and δ-tocotrienol (δTE), i.e., δT-13’-carboxychromanol (COOH) and δTE-13’-COOH, respectively, inhibit COX-1/-2 and 5-LOX activity, but the nature of how they inhibit 5-LOX is not clear. Further, the impact of tocopherols and tocotrienols on COX-1/-2 or 5-LOX activity has not been fully delineated. In this study, we found that tocopherols and tocotrienols inhibited human recombinant COX-1 with IC50s of 1–12 µM, and suppressed COX-1-mediated formation of thromboxane in collagen-stimulated rat's platelets with IC50s of 8–50 µM. None of the vitamin E forms directly inhibited COX-2 activity. 13’-COOHs inhibited COX-1 and COX-2 enzyme activity with IC50s of 3–4 and 4–10 µM, respectively, blocked thromboxane formation in collagen- and ionophore-stimulated rats’ platelets with IC50s of 1.5-2.5 µM, and also inhibited COX-2-mediated prostaglandins in stimulated cells. Using enzyme kinetics, we observed that δT-13’-COOH, δTE-13’-COOH and δTE competitively inhibited 5-LOX activity with Ki of 1.6, 0.8 and 2.2 µM, respectively. These compounds decreased leukotriene B4 from stimulated neutrophil-like cells without affecting translocation of 5-LOX from cytosol to the nucleus. Our study reveals inhibitory effects of vitamin E forms and 13’-COOHs on COX-1 activity and thromboxane formation in platelets, and elucidates mechanisms underlying their inhibition of 5-LOX. These observations are useful for understanding the role of these compounds in disease prevention and therapy.
The gut microbiome is widely recognized as a dynamic organ with a profound influence on human physiology and pathology. Extensive epidemiological and longitudinal cohort studies have provided ...compelling evidence that disruptions in the early-life microbiome can have long-lasting health implications. Various factors before, during, and after birth contribute to shaping the composition and function of the neonatal and infant microbiome. While these alterations can be partially restored over time, metabolic phenotypes may persist, necessitating research to identify the critical period for early intervention to achieve phenotypic recovery beyond microbiome composition. In this review, we provide current understanding of changes in the gut microbiota throughout life and the various factors affecting these changes. Specifically, we highlight the profound impact of early-life gut microbiota disruption on the development of diseases later in life and discuss perspectives on efforts to recover from such disruptions. BMB Reports 2023; 56(9): 469-481.
Chronic diseases contribute to 68% of global mortality, highlighting the importance of early detection and management of conditions such as metabolic syndrome. Effective lifestyle interventions, ...particularly through mobile health (mHealth), have shown potential in promoting health and reducing cardiometabolic risk. This study utilized mHealth data from public health centers in South Korea, targeting adults with risk factors for metabolic syndrome. The Intervention-Motivation-Behavioral skills (IMB) theoretical model was applied to categorize participants’ practice patterns over time using the Group-Based Trend Model (GBTM). And the Generalized Estimating Equations (GEE) methodology was applied to confirm the effective practice patterns for improving metabolic syndrome. Data were collected over 24 weeks. The dataset encompasses life-log data capable of capturing changes in intervention, self-report surveys, and clinical measurements, all linked to personal identification keys and thereby integrated. Participants demonstrated improved health behaviors, with the healthy eating score increasing from 5.0 to 6.4 and physical activity rates rising from 41.5% to 59%. Health risk factors decreased significantly, with the mean number of risk factors dropping from 2.4 to 1.4. The percentage of subjects with three or more metabolic syndrome components decreased from 42.3% in the initial period to 19.2% in the final period. Practice patterns by IMB components were classified into three categories: continuous type, late decline type, and early decline type. Improvements in health behavior and metabolic syndrome were observed in the continuous type of each IMB component. The mHealth interventions were confirmed to be positively associated with improved health behavior and management of metabolic syndrome in the continuous practice patterns of IMB.
Amyotrophic lateral sclerosis (ALS) is a devastating disorder in which motor neurons degenerate, the causes of which remain unclear. In particular, the basis for selective vulnerability of spinal ...motor neurons (sMNs) and resistance of ocular motor neurons to degeneration in ALS has yet to be elucidated. Here, we applied comparative multi-omics analysis of human induced pluripotent stem cell-derived sMNs and ocular motor neurons to identify shared metabolic perturbations in inherited and sporadic ALS sMNs, revealing dysregulation in lipid metabolism and its related genes. Targeted metabolomics studies confirmed such findings in sMNs of 17 ALS (SOD1, C9ORF72, TDP43 (TARDBP) and sporadic) human induced pluripotent stem cell lines, identifying elevated levels of arachidonic acid. Pharmacological reduction of arachidonic acid levels was sufficient to reverse ALS-related phenotypes in both human sMNs and in vivo in Drosophila and SOD1
mouse models. Collectively, these findings pinpoint a catalytic step of lipid metabolism as a potential therapeutic target for ALS.
We set out to determine the usability of serum neurofilament light chain (sNfL), serum glial fibrillary acidic protein (sGFAP), and retinal parameters by using optical coherence tomography (OCT) as ...reliable biomarkers of the progression of oxaliplatin-induced peripheral neuropathy (OIPN). Forty-three patients scheduled to undergo oxaliplatin-based chemotherapy at the National Cancer Center of Korea between June 2018 and October 2019 were prospectively assessed at baseline, 3 months, and 6 months of chemotherapy. Patients were assessed on clinical scales and underwent OCT, sNfL, and sGFAP level measurement at each follow-up visit. By applying the National Cancer Institute-Common Toxicity Criteria (NCI-CTC), OIPN was classified as grade 1 in 12 (28%) patients, grade 2 in 25 (58%), and grade 3 in 5 (12%) at 6 months of chemotherapy. sNfL levels increased during oxaliplatin administration, while serial sGFAP levels or retinal parameters did not change. Patients with grade-3 OIPN showed significantly higher mean sNfL levels than patients with grade 0-2 OIPN at 6 months of treatment. At 4-6 months after completion of chemotherapy, sNfL levels were significantly reduced compared to the levels at 6 months of chemotherapy. Monitoring of sNfL during chemotherapy can indicate ongoing neuroaxonal injury and the severity of OIPN.
Technological advances have increased the availability of diverse digital health services. However, digital health benefits are not equally accessible. Recent studies have focused on digital health ...equity. Researchers are progressively identifying digital determinants of health (DDoH) to address potential health disparities stemming from digital health. This study investigated the determinants of disparities in app-based digital health within the framework of an ecological model. The method proposed by Arksey and O’Malley was adopted in this review. The PubMed, Embase, Scopus, and Google Scholar databases were searched from January 2016 to December 2021. Two reviewers independently screened and selected topics according to the guidelines for the scope of the topic. A consensus was reached to reconcile the differences, and the findings were collated, synthesized, summarized, and reported. This study identified 21 studies pertaining to health equity in app-based digital health. Seven countries were included in this study. Health inequities caused by the adoption of app-based digital health can be reflected in the following three levels according to the ecological model. At the individual level (N = 20), it was influenced by sociodemographic characteristics and digital literacy factors. At the interpersonal level (N = 10), factors such as feedback mechanisms, monitoring, communication modalities, technology-sharing practices, and standardized design were observed. At the community or social level (N = 7), disparities were noted in residential locality, integrated network infrastructure, and Internet accessibility. Finally, digital health policies should consider determinants of digital health inequalities. Ensuring health equity in digital health requires the equitable implementation and measurement of health outcomes through an equity lens. Based on the findings of this study, it is essential to maintain a continued focus on digital health to prevent the further widening of health disparities.
NF-κB plays a central role in pathogenesis of inflammation and cancer. Many phytochemicals, including γ-tocotrienol (γTE), a natural form of vitamin E, have been shown to inhibit NF-κB activation, ...but the underlying mechanism has not been identified. In this study, we show that γTE inhibited cytokine-triggered activation of NF-κB and its upstream regulator TGF-β-activated kinase-1 in murine RAW 264.7 macrophages and primary bone marrow-derived macrophages. In these cells, γTE induced upregulation of A20, an inhibitor of NF-κB. Knockout of A20 partially diminished γTE's anti-NF-κB effect, but γTE increased another NF-κB inhibitor, Cezanne, in A20(-/-) cells. In search of the reason for A20 upregulation, we found that γTE treatment increased phosphorylation of translation initiation factor 2, IκBα, and JNK, indicating induction of endoplasmic reticulum stress. Liquid chromatography-tandem mass spectrometry analyses revealed that γTE modulated sphingolipids, including enhancement of intracellular dihydroceramides, sphingoid bases in de novo synthesis of the sphingolipid pathway. Chemical inhibition of de novo sphingolipid synthesis partially reversed γTE's induction of A20 and the anti-NF-κB effect. The importance of dihydroceramide increase is further supported by the observation that C8-dihydroceramide mimicked γTE in upregulating A20, enhancing endoplasmic reticulum stress, and attenuating TNF-triggered NF-κB activation. Our study identifies a novel anti-NF-κB mechanism where A20 is induced by stress-induced adaptive response as a result of modulation of sphingolipids, and it demonstrates an immunomodulatory role of dihydrocermides.
Purpose
Transforming growth factor beta 1 (TGF-β1) is an important cytokine released after ocular surface injury to promote wound healing. However, its persistence at the injury site triggers a ...fibrotic response that leads to corneal scarring and opacity. Thiazolidinediones (TZDs) are synthetic peroxisome proliferator-activated receptor gamma (PPAR-γ) ligands used to regulate glucose and lipid metabolism in the management of type 2 diabetes. Studies have also showed TZDs have antifibrotic effect. In this study, we investigated the antifibrotic effect of the TZD lobeglitazone on TGF-β1-induced fibrosis in corneal fibroblasts.
Methods
Human primary corneal fibroblasts were cultivated and treated with TGF-β1 (5 ng/mL) to induce fibrosis, with or without pre-treatments with different concentrations of lobeglitazone. Myofibroblast differentiation and extracellular matrix (ECM) protein expression was evaluated by western blotting, immunofluorescence, real-time PCR, and collagen gel contraction assay. The effect of lobeglitazone on TGF-β1-induced reactive oxygen species (ROS) generation was evaluated by DCFDA–cellular ROS detection assay kit. Signaling proteins were evaluated by western blotting to determine the mechanism underlying the antifibrotic effect.
Results
Our results showed lobeglitazone attenuated TGF-β1-induced ECM synthesis and myofibroblast differentiation of corneal fibroblasts. This antifibrotic effect appeared to be independent of PPAR signaling and rather due to the inhibition of the TGF-β1-induced Smad signaling. Lobeglitazone also blocked TGF-β1-induced ROS generation and nicotinamide adenine dinucleotide phosphate oxidase (Nox) 4 transcription.
Conclusion
These findings indicate that lobeglitazone may be a promising therapeutic agent for corneal scarring.
Key messages
Vitamin E forms are substantially metabolized to various carboxychromanols including 13′-carboxychromanols (13′-COOHs) that are found at high levels in feces. However, there is limited knowledge ...about functions of these metabolites. Here we studied δT-13′-COOH and δTE-13′-COOH, which are metabolites of δ-tocopherol and δ-tocotrienol, respectively. δTE-13′-COOH is also a natural constituent of a traditional medicine Garcinia Kola. Both 13′-COOHs are much stronger than tocopherols in inhibition of pro-inflammatory and cancer promoting cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), and in induction of apoptosis and autophagy in colon cancer cells. The anticancer effects by 13′-COOHs appeared to be partially independent of inhibition of COX-2/5-LOX. Using liquid chromatography tandem mass spectrometry, we found that 13′-COOHs increased intracellular dihydrosphingosine and dihydroceramides after short-time incubation in HCT-116 cells, and enhanced ceramides while decreased sphingomyelins during prolonged treatment. Modulation of sphingolipids by 13′-COOHs was observed prior to or coinciding with biochemical manifestation of cell death. Pharmaceutically blocking the increase of these sphingolipids partially counteracted 13′-COOH-induced cell death. Further, 13′-COOH inhibited dihydroceramide desaturase without affecting the protein expression. In agreement with these mechanistic findings, δTE-13′-COOH significantly suppressed the growth and multiplicity of colon tumor in mice. Our study demonstrates that 13′-COOHs have anti-inflammatory and anticancer activities, may contribute to in vivo anticancer effect of vitamin E forms and are promising novel cancer prevention agents.
Display omitted
•13′-Carboxychromanols are dual inhibitors of cyclooxygenase and 5-lipoxygenase.•13′-Carboxychromanols induced cancer cell death via modulation of sphingolipids.•δTE-13′-carboxychromanol, a δ-tocotrienol derivative and found in Garcinia Kola, suppressed colon tumorigenesis in mice.
Roles for the non-coding small RNA RyhB in quorum-sensing and iron-dependent gene modulation in the human pathogen V. vulnificus were assessed in this study. Both the quorum sensing master regulator ...SmcR and the Fur-iron complex were observed to bind to the region upstream of the non-coding small RNA RyhB gene to repress expression, which suggests that RyhB is associated with both quorum-sensing and iron-dependent signaling in this pathogen. We found that expression of LuxS, which is responsible for the biosynthesis of autoinducer-2 (AI-2), was higher in wild type than in a ryhB-deletion isotype. RyhB binds directly to the 5'-UTR (untranslated region) of the luxS transcript to form a heteroduplex, which not only stabilizes luxS mRNA but also disrupts the secondary structure that normally obscures the translational start codon and thereby allows translation of LuxS to begin. The binding of RyhB to luxS mRNA requires the chaperone protein Hfq, which stabilizes RyhB. These results demonstrate that the small RNA RyhB is a key element associated with feedback control of AI-2 production, and that it inhibits quorum-sensing signaling in an iron-dependent manner. This study, taken together with previous studies, shows that iron availability and cell density signals are funneled to SmcR and RyhB, and that these regulators coordinate cognate signal pathways that result in the proper balance of protein expression in response to environmental conditions.
PDF
