Publications by authors named "Hiroyuki Nakamura"

645 Publications

Metalloelastase-12 is involved in the temporomandibular joint inflammatory response as well as cartilage degradation by aggrecanases in STR/Ort mice.

Biomed Rep 2021 Jun 1;14(6):51. Epub 2021 Apr 1.

Department of Oral and Maxillofacial Surgery, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa 920-8640, Japan.

Temporomandibular joint dysfunction (TMJD) is characterised by clinical symptoms involving both the masticatory muscles and the temporomandibular joint (TMJ). Disc internal derangement and osteoarthritis (OA) are the most common forms of TMJD. Currently, the molecular process associated with degenerative changes in the TMJ is unclear. Our previous study showed that elastin-digested peptides act on human TMJ synovial cells and lead to upregulation of interleukin-6 (IL-6) and metalloelastase-12 (MMP-12; an elastin-degrading enzyme) . However, there is limited information regarding the involvement of elastin-degradation by MMP-12 in the processes of inflammatory responses and cartilage degradation . STR/Ort mice were used as a model of TMJ OA in the present study. Significant articular cartilage degeneration was observed starting at 20 weeks of age in the STR/Ort mice and this progressed gradually until 40 weeks, compared with the age-matched CBA mice. Immunostaining analysis showed that MMP-12 and IL-6 were expressed in the chondrocytes in the superficial zones of the cartilage. Immunostaining also showed that aggrecanases [a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4 and ADAMTS-5] were expressed in the chondrocytes in the superficial zones of the cartilage. These findings suggest that an inflammatory and degradative process was initiated in the TMJ. Harmful mechanical stimuli, particularly pressure, may cause damage to the elastin fibres in the most elastin-rich superficial layer of the articular cartilage. Elastin-digested peptides are then generated as endogenous warning signals and they initiate a pro-inflammatory cascade. This leads to upregulation of pro-inflammatory mediators, such as IL-6 and MMP-12, which further trigger tissue damage resulting in elevated levels of elastin-digested peptides. IL-6 increases expression of the aggrecanases ADAMTS-4 and ADAMTS-5, following cartilage degradation. This leads to the establishment of a positive feedback loop and may result in chronic inflammation and cartilage degradation of the TMJ .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/br.2021.1427DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8042671PMC
June 2021

The association between overweight and prevalence of food allergy in Japanese children: a cross-sectional study.

Environ Health Prev Med 2021 Apr 5;26(1):44. Epub 2021 Apr 5.

Department of Environmental and Preventive Medicine, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.

Background: Food allergy (FA) is a common disease in children, and its prevalence has increased in developed countries. The impact of overweight on children health also becomes an important social problem. However, the relationship between overweight and FA is still unclear. We examined the association between overweight and the prevalence of FA among Japanese children.

Methods: We analyzed data obtained using a self-administered questionnaire from 1772 Japanese children. Weight groups according to body mass index cutoff points proposed by the International Obesity Task Force were used to create two groups: overweight and non-overweight. Children were separated into four age groups (3-6 years, 6-9 years, 9-12 years, and 12-15 years) to examine age differences. We performed univariate and multivariate logistic models to examine the association between overweight and FA.

Results: The prevalence of FA was significantly higher in boys (10.6%, p = 0.014) than girls (4.5%) and girls (7.9%, p = 0.012) than boys (2.5%) for 6-9 and 12-15 age groups, respectively. While the prevalence of FA was significantly higher in overweight than non-overweight girls (26.1%, p = 0.005) in the 12-15 age group, no significant difference was found in boys. In girls, overweight was significantly associated with FA after adjustment for age and asthma (odds ratio 1.99, 95% confidence interval 1.01-3.89, p = 0.046).

Conclusions: Our results showed that being overweight was significantly associated with a higher prevalence of FA in girls, but not in boys. Further prospective studies are necessary to find the causal relationship between overweight and FA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12199-021-00960-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8022372PMC
April 2021

Relationship between Vitamin Intake and Health-Related Quality of Life in a Japanese Population: A Cross-Sectional Analysis of the Shika Study.

Nutrients 2021 Mar 22;13(3). Epub 2021 Mar 22.

Department of Environmental and Preventive Medicine, Graduate School of Medical Science, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-8640, Japan.

Although epidemiological studies revealed a relationship between psychosocial states, such as depressive symptoms, and nutritional intake, limited information is currently available on vitamin intake. The Short Form-36 Health Survey (SF-36) is not limited to a specific disease, it is constructed based on a universal concept of health and is used to evaluate the Quality of life (QOL). A three-component scoring method was developed for "Physical component score (PCS)", "Mental component score (MCS)", and "Role/social score (RCS)". Collectively, these summary scores are called the "QOL summary score", which is regarded as a more detailed health summary score. In the present study, we aimed at epidemiologically examine the relationship between vitamin intake and QOL in middle-aged and elderly population in 3162 residents in Japan. In women, a multiple regression analysis showed a positive correlation between all vitamin intake and PCS scores, and between vitamin B6, folic acid, vitamin C, and MCS scores. In consideration of depression as MCS of SF-36 and chronic pain as PCS, an insufficient vitamin intake may affect QOL in women; however, a causal relationship has not yet been demonstrated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu13031023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8004289PMC
March 2021

Synthesis of Bis(Carboranyl)amides 1,1'-μ-(CHNH(O)C(CH)-1,2-CBH) ( = 0, 1) and Attempt of Synthesis of Gadolinium Bis(Dicarbollide).

Molecules 2021 Mar 2;26(5). Epub 2021 Mar 2.

A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Str., 119991 Moscow, Russia.

Bis(carboranyl)amides 1,1'-μ-(CHNH(O)C(CH)-1,2-CBH) ( = 0, 1) were prepared by the reactions of the corresponding carboranyl acyl chlorides with ethylenediamine. Crystal molecular structure of 1,1'-μ-(CHNH(O)C-1,2-CBH) was determined by single crystal X-ray diffraction. Treatment of bis(carboranyl)amides 1,1'-μ-(CHNH(O)C(CH)-1,2-CBH) with ammonium or cesium fluoride results in partial deboronation of the -carborane cages to the -carborane ones with formation of [7,7'(8')-μ-(CHNH(O)C(CH)-7,8-CBH)]. The attempted reaction of [7,7'(8')-μ-(CHNH(O)CCH-7,8-CBH)] with GdCl in 1,2-dimethoxy- ethane did not give the expected metallacarborane. The stability of different conformations of Gd-containing metallacarboranes has been estimated by quantum-chemical calculations using [3,3-μ-DME-3,3'-Gd(1,2-CBH)] as a model. It was found that in the most stable conformation the CH groups of the dicarbollide ligands are in -orientation with respect to the DME ligand, while any rotation of the dicarbollide ligand reduces the stability of the system. This makes it possible to rationalize the design of carborane ligands for the synthesis of gadolinium metallacarboranes on their base.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules26051321DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7958119PMC
March 2021

Shifts in morphology, gene expression, and selection underlie web loss in Hawaiian Tetragnatha spiders.

BMC Ecol Evol 2021 03 22;21(1):48. Epub 2021 Mar 22.

Department of Environmental Science, Policy and Management, University of California, Berkeley, 130 Mulford Hall, #3114, Berkeley, CA, 94720-3114, USA.

Background: A striking aspect of evolution is that it often converges on similar trajectories. Evolutionary convergence can occur in deep time or over short time scales, and is associated with the imposition of similar selective pressures. Repeated convergent events provide a framework to infer the genetic basis of adaptive traits. The current study examines the genetic basis of secondary web loss within web-building spiders (Araneoidea). Specifically, we use a lineage of spiders in the genus Tetragnatha (Tetragnathidae) that has diverged into two clades associated with the relatively recent (5 mya) colonization of, and subsequent adaptive radiation within, the Hawaiian Islands. One clade has adopted a cursorial lifestyle, and the other has retained the ancestral behavior of capturing prey with sticky orb webs. We explore how these behavioral phenotypes are reflected in the morphology of the spinning apparatus and internal silk glands, and the expression of silk genes. Several sister families to the Tetragnathidae have undergone similar web loss, so we also ask whether convergent patterns of selection can be detected in these lineages.

Results: The cursorial clade has lost spigots associated with the sticky spiral of the orb web. This appears to have been accompanied by loss of silk glands themselves. We generated phylogenies of silk proteins (spidroins), which showed that the transcriptomes of cursorial Tetragnatha contain all major spidroins except for flagelliform. We also found an uncharacterized spidroin that has higher expression in cursorial species. We found evidence for convergent selection acting on this spidroin, as well as genes involved in protein metabolism, in the cursorial Tetragnatha and divergent cursorial lineages in the families Malkaridae and Mimetidae.

Conclusions: Our results provide strong evidence that independent web loss events and the associated adoption of a cursorial lifestyle are based on similar genetic mechanisms. Many genes we identified as having evolved convergently are associated with protein synthesis, degradation, and processing, which are processes that play important roles in silk production. This study demonstrates, in the case of independent evolution of web loss, that similar selective pressures act on many of the same genes to produce the same phenotypes and behaviors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12862-021-01779-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7983290PMC
March 2021

Alcohol Intake Is Associated With Elevated Serum Levels of Selenium and Selenoprotein P in Humans.

Front Nutr 2021 22;8:633703. Epub 2021 Feb 22.

Department of Endocrinology and Metabolism, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan.

Selenoprotein P is a hepatokine with antioxidative properties that eliminate a physiologic burst of reactive oxygen species required for intracellular signal transduction. Serum levels of selenoprotein P are elevated during aging and in people with type 2 diabetes, non-alcoholic fatty liver disease, and hepatitis C. However, how serum levels of full-length selenoprotein P are regulated largely remains unknown, especially in the general population. To understand the significance of serum selenoprotein P levels in the general population, we evaluated intrinsic and environmental factors associated with serum levels of full-length selenoprotein P in 1,183 subjects participating in the Shika-health checkup cohort. Serum levels of selenium were positively correlated with liver enzymes and alcohol intake and negatively correlated with body mass index. Serum levels of selenoprotein P were positively correlated with age, liver enzymes, and alcohol intake. In multiple regression analyses, alcohol intake was positively correlated with serum levels of both selenium and selenoprotein P independently of age, gender, liver enzymes, and fatty liver on ultrasonography. In conclusion, alcohol intake is associated with elevated serum levels of selenium and selenoprotein P independently of liver enzyme levels and liver fat in the general population. Moderate alcohol intake may exert beneficial or harmful effects on health, at least partly by upregulating selenoprotein P. These findings increase our understanding of alcohol-mediated redox regulation and form the basis for the adoption of appropriate drinking guidelines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnut.2021.633703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7937717PMC
February 2021

Lysosome-associated membrane protein 3 misexpression in salivary glands induces a Sjögren's syndrome-like phenotype in mice.

Ann Rheum Dis 2021 Mar 3. Epub 2021 Mar 3.

AAV Biology Section, National Institute of Dental and Craniofacial Research, Bethesda, Maryland, USA

Objectives: Sjögren's syndrome (SS) is an autoimmune sialadenitis with unknown aetiology. Although extensive research implicated an abnormal immune response associated with lymphocytes, an initiating event mediated by salivary gland epithelial cell (SGEC) abnormalities causing activation is poorly characterised. Transcriptome studies have suggested alternations in lysosomal function are associated with SS, but a cause and effect linkage has not been established. In this study, we demonstrated that altered lysosome activity in SGECs by expression of lysosome-associated membrane protein 3 (LAMP3) can initiate an autoimmune response with autoantibody production and salivary dysfunction similar to SS.

Methods: Retroductal cannulation of the submandibular salivary glands with an adeno-associated virus serotype 2 vector encoding LAMP3 was used to establish a model system. Pilocarpine-stimulated salivary flow and the presence of autoantibodies were assessed at several time points post-cannulation. Salivary glands from the mice were evaluated using RNAseq and histologically.

Results: Following LAMP3 expression, saliva flow was significantly decreased and serum anti-Ro/SSA and La/SSB antibodies could be detected in the treated mice. Mechanistically, LAMP3 expression increased apoptosis in SGECs and decreased protein expression related to saliva secretion. Analysis of RNAseq data suggested altered lysosomal function in the transduced SGECs, and that the cellular changes can chemoattract immune cells into the salivary glands. Immune cells were activated via toll-like receptors by damage-associated molecular patterns released from LAMP3-expressing SGECs.

Conclusions: These results show a critical role for lysosomal trafficking in the development of SS and establish a causal relationship between LAMP3 misexpression and the development of SS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/annrheumdis-2020-219649DOI Listing
March 2021

Protein intake in inhabitants with regular exercise is associated with sleep quality: Results of the Shika study.

PLoS One 2021 26;16(2):e0247926. Epub 2021 Feb 26.

Department of Environmental and Preventive Medicine, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan.

Study Objectives: Although associations between sleep quality and environmental factors and nutrient intake have been reported, interactions between these factors have not been elucidated in detail. Therefore, this cross-sectional study examined the effects of regular exercise and nutrient intake on sleep quality using the Pittsburgh Sleep Quality Index (PSQI), which is the most frequently used index for sleep evaluation.

Methods: The participants included 378 individuals aged 40 years or older living in Shika Town, Ishikawa Prefecture. Of these individuals, 185 met the inclusion criteria. The participants completed a self-administered questionnaire assessing lifestyle habits and frequency and duration of exercise, the PSQI, and the brief-type self-administered diet history questionnaire (BDHQ) on nutrient intake.

Results: A two-way analysis of covariance on regular exercise and PSQI scores indicated that protein intake (17.13% of energy) was significantly higher in the regular exercise and PSQI ≤10 groups than in the non-regular exercise or PSQI ≥11 groups (p = 0.002). In a multiple logistic regression analysis with PSQI scores (≤10 and ≥11), protein intake was a significant independent variable in any of the models adjusted for confounding factors such as age, sex, body mass index, current smoker, and current drinker (OR: 1.357, 95% CI: 1.081, 1.704, p = 0.009) in the regular exercise group but not in the non-regular exercise group.Conclusions We identified a positive relationship between sleep quality and protein intake in the regular exercise group. These findings suggest that regular exercise at least twice a week for 30 minutes or longer combined with high protein intake contributes to good sleep quality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247926PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909647PMC
February 2021

Py-FITC: a new fluorescent probe for live cell imaging of collagen-rich tissues and ionocytes.

Open Biol 2021 Feb 10;11(2):200241. Epub 2021 Feb 10.

Graduate School of Pharmaceutical Sciences, Chiba University, Japan.

Polypyrrole-based polyamides are used as sequence-specific DNA probes. However, their cellular uptake and distribution are affected by several factors and have not been extensively studied . Here, we generated a series of fluorescence-conjugated polypyrrole compounds and examined their cellular distribution using live zebrafish and cultured human cells. Among the evaluated compounds, Py-FITC was able to visualize collagen-rich tissues, such as the jaw cartilage, opercle and bulbus arteriosus, in early-stage living zebrafish embryos. Then, we stained cultured human cells with Py-FITC and found that the staining became more intense as the amount of collagen was increased. In addition, Py-FITC-stained HR cells, which represent a type of ionocyte on the body surface of living zebrafish embryos. Py-FITC has low toxicity, and collagen-rich tissues and ionocytes can be visualized when soaked in Py-FITC solution. Therefore, Py-FITC may be a useful live imaging tool for detecting changes in collagen-rich tissue and ionocytes, including their mammalian analogues, during both normal development and disease progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsob.200241DOI Listing
February 2021

Ginger facilitates cell migration and heat tolerance in mouse fibroblast cells.

Mol Med Rep 2021 Apr 4;23(4). Epub 2021 Feb 4.

Department of Environmental Physiology, School of Medicine, Shimane University, Izumo, Shimane 693‑8501, Japan.

The components of ginger root ( Roscoe) are widely used for various medicinal purposes. Several bioactive compounds have been identified in ginger, including 6‑, 8‑ and 10‑gingerols, and 6‑shogaol, which are agonists of the thermo‑sensors transient receptor potential (TRP) cation channel subfamily V member 1 and TRP ankyrin 1. Our previous study demonstrated that ginger powder may affect human metabolism . However, the effects of the bioactive compounds of ginger on cells have not been completely elucidated. The present study investigated whether ginger powder extracts could modify cell functions in mouse fibroblast cells. The active components of ginger powder extracts were characterized using high‑performance liquid chromatography. The activation of protein kinases, actin assembly, cell migration, expression levels of heat shock proteins (HSPs) and cell viability after heat shock were analyzed in NIH3T3 mouse fibroblast cells. Subsequently, 6‑, 8‑, 10‑ and 12‑gingerols, as well as 6‑, 8‑ and 10‑shogaols, were detected in ginger powder extracts. The levels of phosphorylated Akt, mTOR, ERK and p38 MAPK increased after a 10‑min stimulation with ginger powder extracts. In addition, HSP expression levels, lamellipodia formation occurring at cell edges, cell migration and tolerance against heat shock were facilitated following ginger powder extract stimulation. These results suggest that ginger modified cell functions, including actin assembly and heat tolerance, .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/mmr.2021.11889DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7893714PMC
April 2021

Beneficial effects of primidone in Niemann-Pick disease type C (NPC)-model cells and mice: Reduction of unesterified cholesterol levels in cells and extension of lifespan in mice.

Eur J Pharmacol 2021 Apr 24;896:173907. Epub 2021 Jan 24.

Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba, 260-8675, Japan.

Niemann-Pick disease type C (NPC) is caused by a loss of function of either NPC1 or NPC2 protein, resulting in the accumulation of unesterified, free-cholesterol (free-C) in cells/tissues and thus leading to cell/tissue damage. In the brain of patients/animals with NPC, as a consequence of the accumulation of free-C in late endosomes/lysosomes (LE/LY) in cells, multiple lipids including complex sphingolipids are accumulated, and almost all patients/animals ultimately develop progressive/fatal neurodegeneration. Several reagents that are considered to act in the brain show beneficial effects on NPC-model animals. In the present study, we investigated the effects of antiepileptic drugs, such as primidone and valproic acid, on the accumulation of free-C in NPC1-null CHO cells and NPC1* fibroblasts, human fibroblasts established from a patient with NPC1 mutation. Like valproic acid, treatment with primidone reduced free-C levels in LE/LY in NPC1-null/mutant cells. Down-regulation of cholesterol ester levels in NPC1-null cells and up-regulation of HMG-CoA reductase and low-density lipoprotein receptor mRNA levels in NPC1* cells were partially recovered by primidone treatment. Thus, primidone was suggested to enhance free-C trafficking from LE/LY to endoplasmic reticulum in NPC1-null/mutant cells. In NPC1-null mice, oral application of primidone (100 mg/kg/day) extended lifespan by approximately 5 days, although the first days showing ataxia, a typical symptom of neuromotor dysfunction, were not affected. Our findings suggest the potential of primidone for the treatment of NPC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejphar.2021.173907DOI Listing
April 2021

Rapid and Mild Lactamization Using Highly Electrophilic Triphosgene in a Microflow Reactor.

Chemistry 2021 Jan 26. Epub 2021 Jan 26.

Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.

Lactams are cyclic amides that are indispensable as drugs and as drug candidates. Conventional lactamization includes acid-mediated and coupling-agent-mediated approaches that suffer from narrow substrate scope, much waste, and/or high cost. Inexpensive, less-wasteful approaches mediated by highly electrophilic reagents are attractive, but there is an imminent risk of side reactions. Herein, a methods using highly electrophilic triphosgene in a microflow reactor that accomplishes rapid (0.5-10 s), mild, inexpensive, and less-wasteful lactamization are described. Methods A and B, which use N-methylmorpholine and N-methylimidazole, respectively, were developed. Various lactams and a cyclic peptide containing acid- and/or heat-labile functional groups were synthesized in good to high yields without the need for tedious purification. Undesired reactions were successfully suppressed, and the risk of handling triphosgene was minimized by the use of microflow technology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.202100059DOI Listing
January 2021

Synthesis of 4-amino-5-allenylisoxazoles gold(I)-catalysed propargyl aza-Claisen rearrangement.

Org Biomol Chem 2021 02;19(6):1358-1364

School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.

Propargyl aza-Claisen rearrangement of 4-propargylaminoisoxazoles 1 proceeded in the presence of cationic gold(i) catalysts to give 4-amino-5-allenylisoxazoles 2 in good to high yields. The silyl group at the terminal alkyne and a cationic gold(i) catalyst bearing a sterically bulky ligand are essential for the generation of isolable allene intermediates. The N-protection of the generated 4-amino-5-allenylisoxazoles 2 allowed the isolation of 5-allenylisoxazoles 4 that have never been synthesized. N-Propargyl aniline 5 was successfully converted to the corresponding ortho-allenyl aniline 6 under the current reaction conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0ob02544eDOI Listing
February 2021

Hypoxia-inducible factor (HIF) inhibitors: a patent survey (2016-2020).

Expert Opin Ther Pat 2021 Jan 29:1-11. Epub 2021 Jan 29.

cLaboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , Yokohama, Japan.

: Hypoxia-inducible factor (HIF) is a master regulator of oxygen homeostasis. The increased expression of genes targeted by HIF is associated with many human diseases, including ischemic cardiovascular disease, stroke, chronic lung disease, and cancer. : This patent survey summarizes the information about patented HIF inhibitors over the last 5 years. : HIF inhibitors have shown promise for the treatment of hypoxic pulmonary hypertension, a circadian rhythm disorder, calcific aortic valve disease, cerebrovascular accident, and heterotopic ossification. In addition, HIF-2α inhibitors can be used for the treatment or prevention of iron overload disorders, Crohn's disease, ulcerative colitis, and thyroid eye disease, or to improve muscle generation and repair. PT2385 completed phase I clinical trials for the treatment of clear cell renal cell carcinoma. It exerted a higher synergistic inhibitory effect on tumor growth in combination with anti-PD-1 antibody, in comparison with each treatment alone, indicating that effective immunotherapy for solid tumors counteracts of the immunosuppression induced by hypoxia. Therefore, considering the effects of hypoxia on cancer cells, stromal cells, and effector immune cells, it is important to develop inhibitors of molecular pathways activated by hypoxia for successful treatments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/13543776.2021.1874345DOI Listing
January 2021

Design and synthesis of 14 and 15-membered macrocyclic scaffolds exhibiting inhibitory activities of hypoxia-inducible factor 1α.

Bioorg Med Chem 2021 Jan 13;30:115949. Epub 2020 Dec 13.

Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. Electronic address:

Inspired by the privileged molecular skeletons of 14- and 15-membered antibiotics, we adopted a relatively unexplored synthetic approach that exploits alkaloidal macrocyclic scaffolds to generate modulators of protein-protein interactions (PPIs). As mimetics of hot-spot residues in the α-helices responsible for the transcriptional regulation, three hydrophobic sidechains were displayed on each of the four distinct macrocyclic scaffolds generating diversity of their spatial arrangements. Modular assembly of the building blocks followed by ring-closing olefin metathesis reaction and subsequent hydrogenation allowed concise and divergent synthesis of scaffolds 1-4. The 14-membered alkaloidal macrocycles 2-4 demonstrated similar inhibition of hypoxia-inducible factor (HIF)-1α transcriptional activities (IC between 8.7 and 10 µM), and 4 demonstrated the most potent inhibition of cell proliferation in vitro (IC = 12 µM against HTC116 colon cancer cell line). A docking model suggested that 4 could mimic the LLxxL motif in HIF-1α, in which the three sidechains are capable of matching the spatial arrangements of the protein hot-spot residues. Unlike most of the stapled peptides, the 14-membered alkaloidal scaffold has a similar size to the α-helix backbone and does not require additional atoms to induce α-helix mimetic structure. These experimental results underscore the potential of alkaloidal macrocyclic scaffolds featuring flexibly customizable skeletal, stereochemical, substitutional, and conformational properties for the development of non-peptidyl PPI modulators targeting α-helix-forming consensus sequences responsible for the transcriptional regulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bmc.2020.115949DOI Listing
January 2021

A new computerized assessment battery for cognition (C-ABC) to detect mild cognitive impairment and dementia around 5 min.

PLoS One 2020 11;15(12):e0243469. Epub 2020 Dec 11.

Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.

This study aimed to develop a new computerized assessment battery for cognition (C-ABC) to detect mild cognitive impairment (MCI) and dementia. We performed C-ABC in subjects with dementia (n = 422), MCI (n = 145), and normal cognition (NC; n = 574), and analyzed by age stratum (50s, 60s, and 70-85 years). To distinguish MCI from NC, the C-ABC total combined score, which were calculated by dividing the C-ABC total score by the C-ABC required time, revealed the best area under the curves (AUC) at 0.838 and 0.735 in the 50s and 60s age groups, respectively; notably, this entire procedure took approximately 5 min. To distinguish dementia from NC and MCI, the partial items of C-ABC (items 3 + 6 combined score) revealed the best AUCs at 0.910, 0.874, and 0.882 in the 50s, 60s, and 70-85 age groups, respectively. Furthermore, the items 3 + 6 combined score established the best AUC at 0.794 in the 70-85 age group to distinguish MCI from NC; this entire procedure took around 2 min. Hence, this study suggests that C-ABC could be a useful tool for detecting dementia or MCI in a short time.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0243469PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7732101PMC
January 2021

Association Between Serum 25-Hydroxyvitamin D Concentrations and Chronic Pain: Effects of Drinking Habits.

J Pain Res 2020 19;13:2987-2996. Epub 2020 Nov 19.

Department of Public Health, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Ishikawa 920-8640, Japan.

Purpose: Although the explanation for inconsistencies in the reported association between serum 25-hydroxyvitamin D [25(OH)D] levels and chronic pain (CP) has not yet been determined, understanding this discrepancy is necessary for the development of vitamin D supplementation as an effective treatment for CP. The aim of this cross-sectional study was to examine the relationship between 25(OH)D concentrations and CP according to drinking habits in Japanese subjects.

Patients And Methods: We distributed invitation letters to 2314 individuals older than 40 years in Shika town, a rural area in Japan, and 724 subjects (386 females; mean age: 63.9 ± 10.4 years) were recruited. CP was defined as persistent pain lasting at least 3 months in any part of the body. Serum concentrations of 25(OH)D, a biomarker of the vitamin D status, were measured using a radioimmunoassay. A serum 25(OH)D level <20 ng/mL was defined as serum 25(OH)D deficiency. Drinking habits were assessed using a self-administered questionnaire. There were three choices, "rarely drink", "sometimes" and "everyday". Respondents who answered "rarely drink" were labelled as non-drinkers and the others as drinkers.

Results: The prevalence of CP was 40.6%. A significant interaction between CP and drinking habits on 25(OH)D concentrations was observed ( = 0.098). A one-way analysis of covariance was performed to compare 25(OH)D concentrations between the subjects with and without CP in each drinking group, and the serum 25(OH)D levels of subjects with CP were significantly lower than those without CP among drinkers ( = 0.007). A logistic regression analysis revealed a correlation between serum 25(OH)D deficiency and CP in drinkers after adjustments for several confounding factors (odds ratio: 0.499; 95% confidence interval: 0.268 - 0.927; = 0.028).

Conclusion: The present results suggest that low serum 25(OH)D concentrations are associated with the development of CP in drinkers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/JPR.S277979DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7682787PMC
November 2020

Chronic Active Epstein-Barr Virus Infection: Is It Immunodeficiency, Malignancy, or Both?

Cancers (Basel) 2020 Oct 30;12(11). Epub 2020 Oct 30.

Department of Allergy and Clinical Immunology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan.

Chronic active Epstein-Barr virus (EBV) infection (CAEBV) is a rare syndrome characterized by prolonged infectious mononucleosis-like symptoms and elevated peripheral blood EBV DNA load in apparently immunocompetent persons. CAEBV has been primarily reported in East Asia and Latin America, suggesting a genetic predisposition in its pathogenesis. In most cases of CAEBV, EBV induces proliferation of its unusual host cells, T or natural killer (NK) cells. The clinical course of CAEBV is heterogeneous; some patients show an indolent course, remaining in a stable condition for years, whereas others show an aggressive course with a fatal outcome due to hemophagocytic lymphohistiocytosis, multiple organ failure, or progression to leukemia/lymphoma. The pathogenesis of CAEBV is unclear and clinicopathological investigations suggest that it has aspects of both malignant neoplasm and immunodeficiency. Recent genetic analyses of both viral and host genomes in CAEBV patients have led to discoveries that are improving our understanding of the nature of this syndrome. This article summarizes the latest findings on CAEBV and discusses critical unsolved questions regarding its pathogenesis and disease concept.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers12113202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7692233PMC
October 2020

Safety and efficacy of Melissa officinalis extract containing rosmarinic acid in the prevention of Alzheimer's disease progression.

Sci Rep 2020 10 29;10(1):18627. Epub 2020 Oct 29.

Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8640, Japan.

We conducted a randomized placebo-controlled double-blind 24-week trial using Melissa officinalis (M. officinalis) extract richly containing rosmarinic acid (RA) on patients with mild dementia due to Alzheimer's disease (AD) with the aim to examine the safety and tolerability (primary endpoint) of RA (500 mg daily) and its clinical effects and disease-related biomarker changes (secondary endpoints). Patients (n = 23) diagnosed with mild dementia due to probable AD were randomized to either the placebo or M. officinalis extract group. No differences in vital signs or physical and neurologic examination results were detected between the M. officinalis and placebo groups. No serious adverse events occurred. There were no significant differences in cognitive measures; however, the mean Neuropsychiatric Inventory Questionnaire (NPI-Q) score improved by 0.5 points in the M. officinalis group and worsened by 0.7 points in the placebo group between the baseline and 24-week visit, indicating a significant difference (P = 0.012). No significant differences were apparent in disease-related biomarkers between the groups. M. officinalis extract containing 500 mg of RA taken daily was safe and well-tolerated by patients with mild dementia due to AD. Our results suggest that RA may help prevent the worsening of AD-related neuropsychiatric symptoms.Trial registration: The registration number for this clinical trial is UMIN000007734 (16/04/2012).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-73729-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7596544PMC
October 2020

miR-935 Inhibits Oral Squamous Cell Carcinoma and Targets Inositol Polyphosphate-4-phosphatase Type IA (INPP4A).

Anticancer Res 2020 Nov;40(11):6101-6113

Molecular Microbiology Group, Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Japan.

Background/aim: Oral squamous cell carcinoma (OSCC) is a common malignancy with poor prognosis. Therefore, novel therapeutic options are needed to improve prognosis of OSCC. Recently, microRNAs (miRs) have received increasing attention as a potential therapeutic tool for carcinomas. However, no definitive miR-based drugs for patients with OSCC have been reported to date. The aim of this study was to identify new miRs potentially involved in cellular processes associated with OSCC malignancy, which could lead to novel therapeutic strategies.

Materials And Methods: We identified miRs that are modulated in OSCC and possibly regulate OSCC malignancy, using miR microarray on OSCC cell lines.

Results: miR-935 and miR-509-3p were down-regulated in OSCC cell lines and patient tissues. When miR-935 was overexpressed in HSC-3-M3 cells, proliferation, migration, and invasion of the cell line was suppressed, whereas apoptosis was increased. Moreover, we showed that the gene inositol polyphosphate-4-phosphatase type I A (INPP4A) is a potential target whose expression is positively regulated by miR-935.

Conclusion: miR-935 may function as a tumor suppressor by inhibiting OSCC malignancy via INPP4A induction. Therefore, miR-935 can be a new therapeutic candidate for OSCC treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.21873/anticanres.14631DOI Listing
November 2020

Residents living in communities with higher civic participation report higher self-rated health.

PLoS One 2020 23;15(10):e0241221. Epub 2020 Oct 23.

Department of Public Health, Kanazawa University Graduate School of Advanced Preventive Medical Sciences, Kanazawa, Japan.

It has been shown that community-level social capital may affect residents' health. The present mixed ecological study assesses the evidence for an association between the community-level social capital and the individual level of self-rated health. The Hakui City Health Interview Survey targeted 15,242 people aged 40 years and older from 11 communities. Among them, 6578 residents responded to the questionnaire (response rate, 43.2%). We examined whether the community-level social capital (general trust, norm, and civic participation) was associated with the individual level of self-rated health. Overall, 1919 (29.1%) answers of self-rated poor health were identified. Community-level civic participation was negatively associated with poor self-rated health after adjusting for individual demographic factors, individual social capitals, and community-level economic status, whereas community-level general trust, and norm were not significant. The findings suggest the importance of fostering communities with high civic participation to reduce the poor health status of residents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241221PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7584176PMC
December 2020

Rhodium(III)-catalysed decarboxylative C-H functionalization of isoxazoles with alkenes and sulfoxonium ylides.

Org Biomol Chem 2020 Nov;18(42):8625-8628

Laboratory of Chemistry and Life Science, Innovative Institute of Research Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan.

Decarboxylative C-H functionalization of isoxazoles with electron-deficient alkenes and sulfoxonium ylides at the C5 position was achieved in the presence of rhodium(iii) catalysts to give the corresponding alkenylation and acylmethylation products, respectively.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0ob02027cDOI Listing
November 2020

Unconventional critical behaviors at the magnetic phase transition of CoSnS kagomé ferromagnet.

J Phys Condens Matter 2021 Jan;33(1):015801

Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan. Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Egypt.

CoSnS has generated a growing interest as a rare example of the highly uniaxial anisotropic kagomé ferromagnet showing a combination of frustrated-lattice magnetism and topology. Recently, via precise measurements of the magnetization and AC susceptibility we have found a low-field anomalous magnetic phase (A-phase) with very slow spin dynamics that appears just below the Curie temperature (T ). The A-phase hosts high-density domain bubbles after cooling through T as revealed in a previous in-situ Lorentz-TEM study. Here, we present further signatures of the anomalous magnetic transition (MT) at T revealed by a study of the critical behaviors of the magnetization and magnetocaloric effect using a high-quality single crystal. Analyses of numerous magnetization isotherms around T (≃177 K) using different approaches (the modified Arrot plot, Kouvel-Fisher method and magnetocaloric effect) result in consistent critical exponents that do not satisfy the theoretical predictions of standard second-order-MT models. Scaling analyses for the magnetization, magnetic entropy change and field-exponent of the magnetic entropy change, all consistently show low-field deviations below T from the universal curves. Our results reveal that the MT of CoSnS can not be explained as a conventional second-order type and suggest an anomalous magnetic state below T .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-648X/abaf94DOI Listing
January 2021

Anti-cancer strategy targeting the energy metabolism of tumor cells surviving a low-nutrient acidic microenvironment.

Mol Metab 2020 12 30;42:101093. Epub 2020 Sep 30.

Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuou, Ami-machi, Inashiki-gun, Ibaraki, 300-0395, Japan. Electronic address:

Objective: Tumor cells experience hypoxia, acidosis, and hypoglycemia. Metabolic adaptation to glucose shortage is essential to maintain tumor cells' survival because of their high glucose requirement. This study evaluated the hypothesis that acidosis might promote tumor survival during glucose shortage and if so, explored a novel drug targeting metabolic vulnerability to glucose shortage.

Methods: Cell survival and bioenergetics metabolism were assessed in lung cancer cell lines. Our in-house small-molecule compounds were screened to identify those that kill cancer cells under low-glucose conditions. Cytotoxicity against non-cancerous cells was also assessed. Tumor growth was evaluated in vivo using a mouse engraft model.

Results: Acidosis limited the cellular consumption of glucose and ATP, causing tumor cells to enter a metabolically dormant but energetically economic state, which promoted tumor cell survival during glucose deficiency. We identified ESI-09, a previously known exchange protein directly activated by cAMP (EAPC) inhibitor, as an anti-cancer compound that inhibited cancer cells under low-glucose conditions even when associated with acidosis. Bioenergetic studies showed that independent of EPAC inhibition, ESI-09 was a safer mitochondrial uncoupler than a classical uncoupler and created a futile cycle of mitochondrial respiration, leading to decreased ATP production, increased ATP dissipation, and fuel scavenging. Accordingly, ESI-09 exhibited more cytotoxic effects under low-glucose conditions than under normal glucose conditions. ESI-09 was also more effective than actively proliferating cells on quiescent glucose-restricted cells. Cisplatin showed opposite effects. ESI-09 inhibited tumor growth in lung cancer engraft mice.

Conclusions: This study highlights the acidosis-induced promotion of tumor survival during glucose shortage and demonstrates that ESI-09 is a novel potent anti-cancer mitochondrial uncoupler that targets a metabolic vulnerability to glucose shortage even when associated with acidosis. The higher cytotoxicity under lower-than-normal glucose conditions suggests that ESI-09 is safer than conventional chemotherapy, can target the metabolic vulnerability of tumor cells to low-glucose stress, and is applicable to many cancer cell types.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molmet.2020.101093DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578269PMC
December 2020

G-quadruplex-proximity protein labeling based on peroxidase activity.

Chem Commun (Camb) 2020 Oct 1;56(78):11641-11644. Epub 2020 Sep 1.

Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, Japan.

Peroxidase-proximity protein labeling was performed using a hemin-parallel G-quadruplex (G4) complex. A tyrosine labeling reaction using an N-methyl luminol derivative was accelerated in close proximity to the hemin with enhanced peroxidase activity by binding to parallel G4. The TERRA-hemin complex activated the labeling of many RNA-binding proteins, including heterogeneous nuclear ribonucleoproteins, in a HeLa cell lysate.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0cc02571bDOI Listing
October 2020

An association study of C9orf3, a novel component of the renin-angiotensin system, and hypertension in diabetes.

Sci Rep 2020 09 30;10(1):16111. Epub 2020 Sep 30.

Department of Environmental and Preventive Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.

The renin-angiotensin system (RAS) is important in the onset and course of cardiovascular, kidney, and metabolic disorders. Previous reports showed that the RAS blockade protects organs and suppress the development of type 2 diabetes mellitus. A novel component of the RAS, namely, chromosome 9 open reading frame 3 (C9orf3), was recently identified, however, its effects are unclear. We evaluated whether the genetic variant of C9orf3 is associated with morbidity of hypertension among subjects with type 2 diabetes. We enrolled 382 subjects with type 2 diabetes, 222 of whom were diagnosed with hypertension. Human leukocyte genomic DNA was isolated and a genetic variant was analyzed for a C/T variant of C9orf3 (rs4385527) via PCR analysis. The relationship between the genotype and hypertension morbidity among subjects with diabetes was examined. The proportion of the respective C9orf3 genetic variants were as follows 247 CC, 119 CT, and 16 TT. The risk of hypertension was determined to be 1.58, with a 95% confidence interval of 1.11-2.27. Moreover, the p value was 0.012 for allelic comparison and for Armitage's trend test, with the C allele identified as the risk factor. Consequently, hypertension was markedly associated with type 2 diabetes in subjects with the C9orf3 variant, exhibiting a nearly 1.6-fold increased risk. The C variant of a new component of the RAS, C9orf3 (rs4385527) might have a considerable impact on the pathogenesis of hypertension in diabetes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-73094-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7528017PMC
September 2020

Treatment of Patients With Non-small-cell Lung Cancer With Uncommon Mutations in Clinical Practice.

Anticancer Res 2020 Oct;40(10):5757-5764

Respiratory Center, Ibaraki Prefectural Central Hospital and Cancer Center, Kasama, Japan.

Background/aim: To describe real clinical outcomes in patients with non-small cell lung cancer who have uncommon epidermal growth factor receptor (EGFR) mutations.

Materials And Methods: We performed a retrospective chart review from 15 medical institutes that cover a population of three million people from April 2008 to March 2019.

Results: There were 102 patients with uncommon EGFR mutation. Progression-free survival (PFS) tended to be longer in patients receiving afatinib compared with first-generation EGFR tyrosine kinase inhibitors. PFS in patients treated with afatinib or osimertinib was significantly longer than in patients treated with gefitinib or erlotinib (p=0.030). Multivariate analysis also revealed the contribution of afatinib or osimertinib to increased survival. In patients with exon 20 insertions, chemotherapy was efficacious.

Conclusion: In treating patients with uncommon EGFR mutations, our results indicate longer-term survival might be achieved with second-generation or later TKIs and cytotoxic chemotherapeutic drugs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.21873/anticanres.14592DOI Listing
October 2020

Impact of Gut Microbiome on Hypertensive Patients With Low-Salt Intake: Shika Study Results.

Front Med (Lausanne) 2020 2;7:475. Epub 2020 Sep 2.

Department of Laboratory Science, Faculty of Health Sciences, Kanazawa University, Kanazawa, Japan.

Salt intake is one of the most important environmental factors impacting hypertension onset. Meanwhile, the potential roles of the gut microbiome (GM) in altering the health status of hosts have drawn considerable attention. Here, we aimed to perform an observational study to investigate the impact of intestinal bacterial flora in hypertensive patients with low-salt or high-salt intake. A total of 239 participants were enrolled, and their gut microbiomes, clinical and demographic details, as well as physiological parameters pertaining to the renin-angiotensin-aldosterone system and inflammatory cytokine profiles, were examined. The participants were classified into four groups based on the presence of different enterotype bacteria, as determined via cluster analysis, and salt intake: low salt/GM enterotype 1, low salt/GM enterotype 2, high salt/GM enterotype 1, and high salt/GM enterotype 2. Results show that the prevalence of hypertension was significantly lower in the low-salt/GM enterotype 2 group (27%) compared to the low salt/GM enterotype 1 group (47%; = 0.04). Alternatively, no significant differences were observed in hypertension prevalence between the two high-salt intake groups (GM enterotype 1 = 50%, GM enterotype 2 = 47%; = 0.83). Furthermore, The low-salt/GM enterotype 2 was higher in the relative abundances of , and the low-salt/GM enterotype 1. differed significantly between the GM enterotypes. These results suggested that consumption of a low-salt diet was ineffective in regulating hypertension in individuals with a specific gut bacteria composition. Our findings support the restoration of GM homeostasis as a new strategy for controlling blood pressure and preventing the development of hypertension.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmed.2020.00475DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7492604PMC
September 2020

Tyrosine-phosphorylation and activation of glucosylceramide synthase by v-Src: Its role in survival of HeLa cells against ceramide.

Biochim Biophys Acta Mol Cell Biol Lipids 2021 01 25;1866(1):158817. Epub 2020 Sep 25.

Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.

Sphingolipids represent a family of cellular lipid-molecules that regulate physiological and pathophysiological processes. Glucosylceramide (GlcCer), the simplest glycosphingolipid (GSL), is synthesized from ceramide and UDP-glucose by GlcCer synthase (GCS). Both GlcCer (and resulting GSLs) and ceramide regulate various cellular functions including cell death and multiple drug resistance. Src family tyrosine kinases are up-regulated in various human cancer cells. We examined the effect of v-Src expression on GCS activity, the formation of 4-nitrobenzo-2-oxa-1,3-diazole (NBD)-labeled GlcCer from NBD-ceramide, and the effect of tyrosine mutation in GCS on ceramide-induced cytotoxicity in HeLa cells. Expression of v-Src increased the formation of NBD-GlcCer in both intact cells without marked changes in other sphingolipid metabolites and cell homogenates without changing affinities of NBD-ceramide and UDP-glucose. Expression of v-Src also increased tyrosine-phosphorylated levels in GCS proteins in HeLa and HEK293T cells. In HEK293T cells transiently expressing the GCS mutant, GCS-Y132F-HA, showing replacement of the tyrosine residue with phenylalanine, tyrosine-phosphorylated levels in GCS proteins were significantly lower than those in control cells expressing the GCS-wild-type-HA. The formation of NBD-GlcCer in HeLa cells stably expressing GCS-Y132F-HA was significantly lower than that in the control. Ceramide-induced cytotoxicity in HeLa-GCS-Y132F-HA cells was significantly greater than in the control. In this study, we showed for the first time that expression of v-Src up-regulated GCS activity via tyrosine phosphorylation of the enzyme in a post-translational manner. Mechanisms of Src-induced resistance to ceramide-induced cytotoxicity are discussed in relation to the Src-induced up-regulation of GCS activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbalip.2020.158817DOI Listing
January 2021