Endurance exercise increases skeletal muscle kynurenine aminotransferases and plasma kynurenic acid in humans
Physical exercise has emerged as an alternative treatment for patients with depressive disorder. Recent animal studies show that exercise protects from depression by increased skeletal muscle kynurenine aminotransferase (KAT) expression which shifts the kynurenine metabolism away from the neurotoxic kynurenine (KYN) to the production of kynurenic acid (KYNA). In the present study, we investigated the effect of exercise on kynurenine metabolism in humans. KAT gene and protein expression was increased in the muscles of endurance-trained subjects compared with untrained subjects. Endurance exercise caused an increase in plasm...
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Schlittler, M., Goiny, M., Agudelo, L. Z., Venckunas, T., Brazaitis, M., Skurvydas, A., Kamandulis, S., Ruas, J. L., Erhardt, S., Westerblad, H., Andersson, D. C. Tags: RAPID REPORT Source Type: research
Endothelial microparticles carrying hedgehog-interacting protein induce continuous endothelial damage in the pathogenesis of acute graft-versus-host disease
In this study, we detected the plasma EMP levels and endothelial damage in patients and mice with aGVHD in vivo and then examined the effects of EMPs derived from injured endothelial cells (ECs) on endothelial damage and the role of hedgehog-interacting protein (HHIP) carried by EMPs in these effects in vitro. Our results showed that EMPs were persistently increased in the early posttransplantation phase in patients and mice with aGVHD. Meanwhile, endothelial damage was continuous in aGVHD mice, but was temporary in non-aGVHD mice after transplantation. In vitro, EMPs induced endothelial damage, including increased EC apop...
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Nie, D.-m., Wu, Q.-l., Zheng, P., Chen, P., Zhang, R., Li, B.-b., Fang, J., Xia, L.-h., Hong, M. Tags: ARTICLES Source Type: research
Novel regulation of equlibrative nucleoside transporter 1 (ENT1) by receptor-stimulated Ca2+-dependent calmodulin binding
Equilibrative nucleoside transporters (ENTs) facilitate the flux of nucleosides, such as adenosine, and nucleoside analog (NA) drugs across cell membranes. A correlation between adenosine flux and calcium-dependent signaling has been previously reported; however, the mechanistic basis of these observations is not known. Here we report the identification of the calcium signaling transducer calmodulin (CaM) as an ENT1-interacting protein, via a conserved classic 1-5-10 motif in ENT1. Calcium-dependent human ENT1-CaM protein interactions were confirmed in human cell lines (HEK293, RT4, U-87 MG) using biochemical assays (HEK29...
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Bicket, A., Mehrabi, P., Naydenova, Z., Wong, V., Donaldson, L., Stagljar, I., Coe, I. R. Tags: ARTICLES Source Type: research
Human vascular endothelial cells transport foreign exosomes from cow's milk by endocytosis
Encapsulation of microRNAs in exosomes confers protection against degradation and a vehicle for shuttling of microRNAs between cells and tissues, and cellular uptake by endocytosis. Exosomes can be found in foods including milk. Humans absorb cow's milk exosomes and deliver the microRNA cargo to peripheral tissues, consistent with gene regulation by dietary nucleic acids across species boundaries. Here, we tested the hypothesis that human vascular endothelial cells transport milk exosomes by endocytosis, constituting a step crucial for the delivery of dietary exosomes and their cargo to peripheral tissues. We tested this h...
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Kusuma, R. J., Manca, S., Friemel, T., Sukreet, S., Nguyen, C., Zempleni, J. Tags: ARTICLES Source Type: research
Alternatively activated macrophages exhibit an anticalcifying activity dependent on extracellular ATP/pyrophosphate metabolism
In conclusion, increased accumulation of extracellular ATP and PPi by alternatively activated mouse M2s inhibits CPD. These results reveal novel mechanisms underlying macrophage-dependent control of intimal calcification. (Source: AJP: Cell Physiology)
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Villa-Bellosta, R., Hamczyk, M. R., Andres, V. Tags: ARTICLES Source Type: research
HDAC2 regulates FoxO1 during RANKL-induced osteoclastogenesis
In conclusion, HDAC2 activates Akt thus suppresses FoxO1 transcription results in enhanced osteoclastogenesis. Our data imply the potential value of HDAC2 as a new target in regulating osteoclast differentiation and function. (Source: AJP: Cell Physiology)
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Dou, C., Li, N., Ding, N., Liu, C., Yang, X., Kang, F., Cao, Z., Quan, H., Hou, T., Xu, J., Dong, S. Tags: CALL FOR PAPERS Source Type: research
Role of protein phosphatases in the run down of guinea pig cardiac Cav1.2 Ca2+ channels
This study aimed to investigate protein phosphatases involved in the run down of Cav1.2 Ca2+ channels. Single ventricular myocytes obtained from adult guinea pig hearts were used to record Ca2+ channel currents with the patch-clamp technique. Calmodulin (CaM) and ATP were used to restore channel activity in inside-out patches. Inhibitors of protein phosphatases were applied to investigate the role of phosphatases. The specific protein phosphatase type 1 (PP1) inhibitor (PP1 inhibitor-2) and protein phosphatase type 2A (PP2A) inhibitor (fostriecin) abolished the slow run down of Cav1.2 Ca2+ channels, which was evident as th...
Source: AJP: Cell Physiology - May 14, 2016 Category: Cytology Authors: Yu, L., Xu, J., Minobe, E., Kameyama, A., Yang, L., Feng, R., Hao, L., Kameyama, M. Tags: CALL FOR PAPERS Source Type: research
The carboxyl-terminally truncated kidney anion exchanger 1 R901X dRTA mutant is unstable at the plasma membrane
Mutations in the SLC4A1 gene coding for kidney anion exchanger 1 (kAE1) cause distal renal tubular acidosis (dRTA). We investigated the fate of the most common truncated dominant dRTA mutant kAE1 R901X. In renal epithelial cells, we found that kAE1 R901X is less abundant than kAE1 wild-type (WT) at the plasma membrane. Although kAE1 WT and kAE1 R901X have similar half-lives, the decreased abundance of kAE1 R901X at the surface is due to an increased endocytosis rate and a decreased recycling rate of endocytosed proteins. We propose that, in polarized renal epithelial cells, the apically mistargeted kAE1 R901X mutant is end...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Almomani, E., Lashhab, R., Alexander, R. T., Cordat, E. Tags: ARTICLES Source Type: research
Downregulation of miR-384-5p attenuates rotenone-induced neurotoxicity in dopaminergic SH-SY5Y cells through inhibiting endoplasmic reticulum stress
In this study, we investigated the role of miR-384-5p in an in vitro model of PD using dopaminergic SH-SY5Y cells treated with rotenone. We found that miR-384-5p was persistently induced by rotenone in neurons. Also, the inhibition of miR-384-5p significantly suppressed rotenone-induced neurotoxicity, while overexpression of miR-384-5p aggravated rotenone-induced neurotoxicity. Through bioinformatics and dual-luciferase reporter assay, miR-384-5p was found to directly target the 3'-untranslated region of glucose-regulated protein 78 (GRP78), the master regulator of ER stress sensors. Quantitative polymerase chain reaction ...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Jiang, M., Yun, Q., Shi, F., Niu, G., Gao, Y., Xie, S., Yu, S. Tags: ARTICLES Source Type: research
Nicotinic modulation of Ca2+ oscillations in rat cortical neurons in vitro
The roles of nicotine on Ca2+ oscillations [intracellular Ca2+ ([Ca2+]i) oscillation] in rat primary cultured cortical neurons were studied. The spontaneous [Ca2+]i oscillations (SCO) were recorded in a portion of the neurons (65%) cultured for 7–10 days in vitro. Application of nicotine enhanced [Ca2+]i oscillation frequency and amplitude, which were reduced by the selective α4β2-nicotinic acetylcholine receptors (nAChRs) antagonist dihydro-β-erythroidine (DHβE) hydrobromide, and the selective α7-nAChRs antagonist methyllycaconitine citrate (MLA, 20 nM). DHβE reduced SCO frequency and...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Wang, J., Wang, Y., Guo, F., Feng, Z., Wang, X., Lu, C. Tags: ARTICLES Source Type: research
Modulation of Ca2+ oscillation and melatonin secretion by BKCa channel activity in rat pinealocytes
The pineal glands regulate circadian rhythm through the synthesis and secretion of melatonin. The stimulation of nicotinic acetylcholine receptor due to parasympathetic nerve activity causes an increase in intracellular Ca2+ concentration and eventually downregulates melatonin production. Our previous report shows that rat pinealocytes have spontaneous and nicotine-induced Ca2+ oscillations that are evoked by membrane depolarization followed by Ca2+ influx through voltage-dependent Ca2+ channels (VDCCs). These Ca2+ oscillations are supposed to contribute to the inhibitory mechanism of melatonin secretion. Here we examined ...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Mizutani, H., Yamamura, H., Muramatsu, M., Hagihara, Y., Suzuki, Y., Imaizumi, Y. Tags: ARTICLES Source Type: research
Iron induces cancer stem cells and aggressive phenotypes in human lung cancer cells
Evidence has accumulated in support of the critical impact of cancer stem cells (CSCs) behind the chemotherapeutic failure, cancer metastasis, and subsequent disease recurrence and relapse, but knowledge of how CSCs are regulated is still limited. Redox status of the cells has been shown to dramatically influence cell signaling and CSC-like aggressive behaviors. Here, we investigated how subtoxic concentrations of iron, which have been found to specifically induce cellular hydroxyl radical, affected CSC-like subpopulations of human non-small cell lung carcinoma (NSCLC). We reveal for the first time that subchronic iron exp...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Chanvorachote, P., Luanpitpong, S. Tags: CALL FOR PAPERS Source Type: research
Involvement of ion channels and transporters in carcinoma angiogenesis and metastasis
Angiogenesis is a finely tuned process, which is the result of the equilibrium between pro- and antiangiogenic factors. In solid tumor angiogenesis, the balance is highly in favor of the production of new, but poorly functional blood vessels, initially intended to provide growing tumors with nutrients and oxygen. Among the numerous proteins involved in tumor development, several types of ion channels are overexpressed in tumor cells, as well as in stromal and endothelial cells. Ion channels thus actively participate in the different hallmarks of cancer, especially in tumor angiogenesis and metastasis. Indeed, from their st...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Martial, S. Tags: REVIEWS Source Type: research
Changing calcium: CRAC channel (STIM and Orai) expression, splicing, and posttranslational modifiers
A wide variety of cellular function depends on the dynamics of intracellular Ca2+ signals. Especially for relatively slow and lasting processes such as gene expression, cell proliferation, and often migration, cells rely on the store-operated Ca2+ entry (SOCE) pathway, which is particularly prominent in immune cells. SOCE is initiated by the sensor proteins (STIM1, STIM2) located within the endoplasmic reticulum (ER) registering the Ca2+ concentration within the ER, and upon its depletion, cluster and trap Orai (Orai1-3) proteins located in the plasma membrane (PM) into ER-PM junctions. These regions become sites of highly...
Source: AJP: Cell Physiology - April 30, 2016 Category: Cytology Authors: Niemeyer, B. A. Tags: THEMES Source Type: research
X-ray diffraction analysis of the effects of myosin regulatory light chain phosphorylation and butanedione monoxime on skinned skeletal muscle fibers
The phosphorylation of the myosin regulatory light chain (RLC) is an important modulator of skeletal muscle performance and plays a key role in posttetanic potentiation and staircase potentiation of twitch contractions. The structural basis for these phenomena within the filament lattice has not been thoroughly investigated. Using a synchrotron radiation source at SPring8, we obtained X-ray diffraction patterns from skinned rabbit psoas muscle fibers before and after phosphorylation of myosin RLC in the presence of myosin light chain kinase, calmodulin, and calcium at a concentration below the threshold for tension develop...
Source: AJP: Cell Physiology - April 14, 2016 Category: Cytology Authors: Yamaguchi, M., Kimura, M., Li, Z.-b., Ohno, T., Takemori, S., Hoh, J. F. Y., Yagi, N. Tags: ARTICLES Source Type: research
