Mechanism of molecular regulation of nuclear -encoded mitochondrial gene expression by electrical stimulation in the cultured neonatal rat cardiac myocytes

To answer the question whether increased energy demand resulting from myocyte hypertrophy and enhanced $\beta$-myosin heavy chain mRNA, contractile protein synthesis and assembly leads to mitochondrial proliferation and differentiation, we set up an electrical stimulation model of cultured neonatal rat cardiac myocytes. We describe, as a result of increased contractile activity, increased mitochondrial profiles, cytochrome oxidase mRNA, and activity, as well as a switch in mitochondrial carnitine palmitoyltransferase-I (CPT-I) from the liver to muscle isoform. We investigate physiological pathways that lead to accumulation of gene transcripts for nuclear encoded mitochondrial proteins in the heart. Cardiomyocytes were stimulated for varying times up to 72 hr in serum-free culture. The mRNA contents for genes associated with transcriptional activation (c-fos, c-jun, junB, nuclear respiratory factor 1 (Nrf-1)), mitochondrial proliferation (cytochrome c (Cyt c), cytochrome oxidase), and mitochondrial differentiation (carnitine palmitonyltransferase I (CPT-I) isoforms) were measured. The results establish a temporal pattern of mRNA induction beginning with c-fos (0.25-3 hr) and followed by c-jun (0.5-3 hr), junB (0.5-6 hr), NRF-1 (1-12 hr), Cyt c (12-72 hr), cytochrome c oxidase (12-72 hr). Induction of the latter was accompanied by a marked decrease in the liver-specific CPT-I mRNA. Electrical stimulation increased c-fos, $\beta$-myosin heavy chain, and Cyt c promoter activities. These increases coincided with a rise in their respective endogenous gene transcripts. NRF-1, cAMP response element (CRE), and Sp-1 site mutations within the Cyt c promoter reduced luciferase expression in both stimulated and nonstimulated myocytes. Mutations in the Nrf-1 and CRE sites inhibited the induction by electrical stimulation or by transfection of c-jun into non-paced cardiac myocytes whereas mutation of the Sp-1 site maintained or increased the fold induction. This is consistent with the appearance of NRF-1 and fos/jun mRNAs prior to that of Cyt c. Overexpression of c-jun by transfection also activates the Nrf-1 and Cyt c mRNA sequentially. Electrical stimulation of cardiac myocytes activates the c-Jun-N-terminal kinase so that the fold-activation of the cyt c promoter is increased by pacing when either c-jun or c-fos/c-jun are cotransfected. We have identified physical association of Nrf-1 protein with the Nrf-1 enhancer element and of c-Jun with the CRE binding sites on the Cyt c promoter. This is the first demonstration that induction of Nrf-1 and c-Jun by pacing of cardiac myocytes directly mediates Cyt c gene expression and mitochondrial proliferation in response to hypertrophic stimuli in the heart.^ Subsequent to gene activation pathways that lead to mitochondrial proliferation, we observed an isoform switch in CPT-I from the liver to muscle mRNA. We have found that the half-life for the muscle CPT-I is not affected by electrical stimulation, but electrical decrease the T1/2 in the liver CPT-I by greater than 50%. This suggests that the liver CPT-I switch to muscle isoform is due to (1) a decrease in T1/2 of liver CPT-I and (2) activation of muscle CPT-Itranscripts by electrical stimulation. (Abstract shortened by UMI.) ^

Inner-Hair Cells Parameterized-Hardware Implementation for Personalized Auditory Nerve Stimulation

In this paper the hardware implementation of an inner hair cell model is presented. Main features of the design are the use of Meddis’ transduction structure and the methodology for Design with Reusability. Which allows future migration to new hardware and design refinements for speech processing and custom-made hearing aids

Distributed System for Cognitive Stimulation Over Interactive TV.

Descripción y evaluación de sistema de estimulación cognitiva a través de la TDT orientada a personas con enfermedad de Parkinson, con supervisión por parte de sus terapeutas de forma remota. Abstract: This paper details the full design, implementation, and validation of an e-health service in order to improve the community health care services for patients with cognitive disorders. Specifically, the new service allows Parkinson’s disease patients benefit from the possibility of doing cognitive stimulation therapy (CST) at home by using a familiar device such as a TV set. Its use instead of a PC could be a major advantage for some patients whose lack of familiarity with the use of a PC means that they can do therapy only in the presence of a therapist. For these patients this solution could bring about a great improvement in their autonomy. At the same time, this service provides therapists with the ability to conduct follow-up of therapy sessions via the web,benefiting from greater and easier control of the therapy exercises performed by patients and allowing them to customize new exercises in accordance with the particular needs of each patient. As a result, this kind of CST is considered to be a complement of other therapies oriented to the Parkinson patients. Furthermore, with small changes, the system could be useful for patients with a different cognitive disease such as Alzheimer’s or mild cognitive impairment.

Effects of binaural stimulation in attention and EEG

When two pure tones of slightly different frequency are presented separately to each ear, the listener perceives a third single tone with amplitude variations at a frequency that equals the difference between the two tones, this perceptual illusion is known as binaural auditory beat. There are anecdotal reports that suggest that the binaural beat can entrain EEG activity and may affect the arousal levels, although few studies have been published. There is a need for double-blind, well-designed studies in order to establish a solid foundation for these sounds, as most of the documented benefits come from self-reported cases that could be affected by placebo effect. As BB’s are a cheap technology (it even exists a free open source programmable bin aural-beat generator on the internet named Gnaural), any achievement in this area could be of public interest. The aim in our research was to explore the potential of BB’s in a particular field: tasks that require focus and concentration. In order to detect changes in the brain waves that could relate to any particular improvement, EEG recordings of a small sample of individuals were also obtained. In this study we compare the effect of different binaural stimulation in 7 EEG frequency ranges, 78 participants were exposed to 20 min binaural beat stimulation. The effects were obtained both qualitative with cognitive test and quantitative with EEG analysis. Results suggest no significant statistical improvement in 20 min stimulation.

Central pain augmentation in fibromyalgia during subjectively-matched mechanical stimulation

The precise pathophysiology of fibromyalgia, a syndrome characterized by, among other symptoms, chronic widespread pain, remains to be elucidated (Abeles et al., 2007). The fact that, when subjected to the same amount of stimulation, patients show enhanced brain responses as compared to controls provides evidence of central pain augmentation in this syndrome. We aimed to characterize brain response differences when stimulation is adjusted to elicit similar subjective levels of pain in both groups.

Effect of binaural stimulation on attention and EEG

When two pure tones of slightly different frequency are presented separately to each ear, the listener perceives a third single tone with amplitude variations at a frequency that equals the difference between the two tones; this perceptual illusion is known as the binaural auditory beat (BB). There are anecdotal reports that suggest that the binaural beat can entrain EEG activity and may affect the arousal levels, although few studies have been published. There is a need for double-blind, well-designed studies in order to establish a solid foundation for these sounds, as most of the documented benefits come from self-reported cases that could be affected by placebo effect. As BBs are a cheap technology (it even exists a free open source programmable binaural- beat generator on the Internet named Gnaural), any achievement in this area could be of public interest. The aim in our research was to explore the potential of BBs in a particular field: tasks that require focus and concentration. In order to detect changes in the brain waves that could relate to any particular improvement, EEG recordings of a small sample of individuals were also obtained. In this study we compare the effect of different binaural stimulation in 7 EEG frequency ranges. 78 participants were exposed to 20-min binaural beat stimulation. The effects were obtained both quali- tative with cognitive test and quantitative with EEG analysis. Results suggest no significant statistical improvement in 20-min stimulation.

Safety study of transcranial static magnetic field stimulation (tSMS) of the human cortex

Transcranial static magnetic field stimulation (tSMS) in humans reduces cortical excitability. Objective: The objective of this study was to determine if prolonged tSMS (2 h) could be delivered safely in humans. Safety limits for this technique have not been described. Methods: tSMS was applied for 2 h with a cylindric magnet on the occiput of 17 healthy subjects. We assessed tSMS-related safety aspects at tissue level by measuring levels of neuron-specific enolase (NSE,a marker of neuronal damage) and S100 (a marker of glial reactivity and damage). We also included an evaluation of cognitive side effects by using a battery of visuomotor and cognitive tests. Results: tSMS did not induce any significant increase in NSE or S100. No cognitive alteration was detected. Conclusions: Our data indicate that the application of tSMS is safe in healthy human subjects, at least within these parameters

Stimulation of renin secretion by nitric oxide is mediated by phosphodiesterase 3

This study aimed to characterize the cellular pathways along which nitric oxide (NO) stimulates renin secretion from the kidney. Using the isolated perfused rat kidney model we found that renin secretion stimulated 4- to 8-fold by low perfusion pressure (40 mmHg), by macula densa inhibition (100 μmol/liter of bumetanide), and by adenylate cyclase activation (3 nmol/liter of isoproterenol) was markedly attenuated by the NO synthase inhibitor nitro-l-arginine methyl ester (l-Name) (1 mM) and that the inhibition by l-Name was compensated by the NO-donor sodium nitroprusside (SNP) (10 μmol/liter). Similarly, inhibition of cAMP degradation by blockade of phosphodiesterase 1 (PDE-1) (20 μmol/liter of 8-methoxymethyl-1-methyl-3-(2-methylpropyl)xanthine) or of PDE-4 (20 μmol/liter of rolipram) caused a 3- to 4-fold stimulation of renin secretion that was attenuated by l-Name and that was even overcompensated by sodium nitroprusside. Inhibition of PDE-3 by 20 μmol/liter of milrinone or by 200 nmol/liter of trequinsin caused a 5- to 6-fold stimulation of renin secretion that was slightly enhanced by NO synthase inhibition and moderately attenuated by NO donation. Because PDE-3 is a cGMP-inhibited cAMP-PDE the role of endogenous cGMP for the effects of NO was examined by the use of the specific guanylate cyclase inhibitor 1-H-(1,2,4)oxodiazolo(4,3a)quinoxalin-1-one (20 μmol). In the presence of 1H-[1,2,4]oxodiazolo[4,3-a]quinoxalin-1-one the effect of NO on renin secretion was abolished, whereas PDE-3 inhibitors exerted their normal effects. These findings suggest that PDE-3 plays a major role for the cAMP control of renin secretion. Our findings are compatible with the idea that the stimulatory effects of endogenous and exogenous NO on renin secretion are mediated by a cGMP-induced inhibition of cAMP degradation.

Stimulation of neurite outgrowth using an electrically conducting polymer

Damage to peripheral nerves often cannot be repaired by the juxtaposition of the severed nerve ends. Surgeons have typically used autologous nerve grafts, which have several drawbacks including the need for multiple surgical procedures and loss of function at the donor site. As an alternative, the use of nerve guidance channels to bridge the gap between severed nerve ends is being explored. In this paper, the electrically conductive polymer—oxidized polypyrrole (PP)—has been evaluated for use as a substrate to enhance nerve cell interactions in culture as a first step toward potentially using such polymers to stimulate in vivo nerve regeneration. Image analysis demonstrates that PC-12 cells and primary chicken sciatic nerve explants attached and extended neurites equally well on both PP films and tissue culture polystyrene in the absence of electrical stimulation. In contrast, PC-12 cells interacted poorly with indium tin oxide (ITO), poly(l-lactic acid) (PLA), and poly(lactic acid-co-glycolic acid) surfaces. However, PC-12 cells cultured on PP films and subjected to an electrical stimulus through the film showed a significant increase in neurite lengths compared with ones that were not subjected to electrical stimulation through the film and tissue culture polystyrene controls. The median neurite length for PC-12 cells grown on PP and subjected to an electrical stimulus was 18.14 μm (n = 5643) compared with 9.5 μm (n = 4440) for controls. Furthermore, animal implantation studies reveal that PP invokes little adverse tissue response compared with poly(lactic acid-co-glycolic acid).

Identification of an intramolecular interaction between small regions in type V adenylyl cyclase that influences stimulation of enzyme activity by Gsα

Using the full-length and two engineered soluble forms (C1-C2 and Cla-C2) of type V adenylyl cyclase (ACV), we have investigated the role of an intramolecular interaction in ACV that modulates the ability of the α subunit of the stimulatory GTP-binding protein of AC (Gsα) to stimulate enzyme activity. Concentration–response curves with Gsα suggested the presence of high and low affinity sites on ACV, which interact with the G protein. Activation of enzyme by Gsα interaction at these two sites was most apparent in the C1a-C2 form of ACV, which lacks the C1b region (K572–F683). Yeast two-hybrid data demonstrated that the C1b region interacted with the C2 region and its 64-aa subdomain, C2I. Using peptides corresponding to the C2I region of ACV, we investigated the role of the C1b/C2I interaction on Gsα-mediated stimulation of C1-C2 and full-length ACV. Our data demonstrate that a 10-aa peptide corresponding to L1042–T1051 alters the profile of the activation curves of full-length and C1-C2 forms of ACV by different Gsα concentrations to mimic the activation profile observed with C1a-C2 ACV. The various peptides used in our studies did not alter forskolin-mediated stimulation of full-length and C1-C2 forms of ACV. We conclude that the C1b region of ACV interacts with the 10-aa region (L1042–T1051) in the C2 domain of the enzyme to modulate Gsα-elicited stimulation of activity.

Signalling through MyD88 drives surface expression of the mycobacterial receptors MCL (Clecsf8, Clec4d) and Mincle (Clec4e) following microbial stimulation

Acknowledgements We would like to thank the staff of the animal facility for their support and care for our animals. Funding was provided by the Wellcome Trust (102705) and Medical Research Council (UK) (MR/J004820/1) and a University of Aberdeen Studentship to BK.

Identification of the salmonid IL-17A/F1a/b, IL-17A/F2b, IL-17A/F3 and IL-17N genes and analysis of their expression following in vitro stimulation and infection

Date of Acceptance: 15/04/2015

Paracrine stimulation of interstitial collagenase (MMP-1) in the human endometrium by interleukin 1α and its dual block by ovarian steroids

In the cycling human endometrium, the expression of interstitial collagenase (MMP-1) and of several related matrix metalloproteinases (MMPs) follows the late-secretory fall in sex steroid plasma concentrations and is thought to be a critical step leading to menstruation. The rapid and extensive lysis of interstitial matrix that precedes menstrual shedding requires a strict control of these proteinases. However, the mechanism by which ovarian steroids regulate endometrial MMPs remains unclear. We report here that, in the absence of ovarian steroids, MMP-1 expression in endometrial fibroblasts is markedly stimulated by medium conditioned by endometrial epithelial cells. This stimulation can be prevented by antibodies directed against interleukin 1α (IL-1α) but not against several other cytokines. Ovarian steroids inhibit the release of IL-1α and repress MMP-1 production by IL-1α-stimulated fibroblasts. In short-term cultures of endometrial explants obtained throughout the menstrual cycle, the release of both IL-1α and MMP-1 is essentially limited to the perimenstrual phase. We conclude that epithelium-derived IL-1α is the key paracrine inducer of MMP-1 in endometrial fibroblasts. However, MMP-1 production in the human endometrium is ultimately blocked by ovarian steroids, which act both upstream and downstream of IL-1α, thereby exerting an effective control via a “double-block” mechanism.

Electrical stimulation of neonatal cardiomyocytes results in the sequential activation of nuclear genes governing mitochondrial proliferation and differentiation

Electrical stimulation of neonatal cardiac myocytes produces hypertrophy and cellular maturation with increased mitochondrial content and activity. To investigate the patterns of gene expression associated with these processes, cardiac myocytes were stimulated for varying times up to 72 hr in serum-free culture. The mRNA contents for genes associated with transcriptional activation [c-fos, c-jun, JunB, nuclear respiratory factor 1 (NRF-1)], mitochondrial proliferation [cytochrome c (Cyt c), cytochrome oxidase], and mitochondrial differentiation [carnitine palmitoyltransferase I (CPT-I) isoforms] were measured. The results establish a temporal pattern of mRNA induction beginning with c-fos (0.25–3 hr) and followed sequentially by c-jun (0.5–3 hr), JunB (0.5–6 hr), NRF-1 (1–12 hr), Cyt c (12–72 hr), and muscle-specific CPT-I (48–72 hr). Induction of the latter was accompanied by a marked decrease in the liver-specific CPT-I mRNA, thus supporting the developmental fidelity of this pattern of gene regulation. Consistent with a transcriptional mechanism, electrical stimulation increased c-fos, β-myosin heavy chain, and Cyt c promoter activities. These increases coincided with a rise in their respective endogenous gene transcripts. NRF-1, cAMP response element, and Sp-1 site mutations within the Cyt c promoter reduced luciferase expression in both stimulated and nonstimulated myocytes. Mutations in the NRF-1 and CRE sites inhibited the induction by electrical stimulation (5-fold and 2-fold, respectively) whereas mutation of the Sp-1 site maintained or increased the fold induction. This finding is consistent with the appearance of NRF-1 and fos/jun mRNAs prior to that of Cyt c and suggests that induction of these transcription factors is a prerequisite for the transcriptional activation of Cyt c expression. These results support a regulatory role for NRF-1 and possibly AP-1 in the initiation of mitochondrial proliferation.

Murine hematopoietic stem cells committed to macrophage/dendritic cell formation: Stimulation by Flk2-ligand with enhancement by regulators using the gp130 receptor chain

The stimulation by Flk2-ligand (FL) of blast colony formation by murine bone marrow cells was selectively potentiated by the addition of regulators sharing in common the gp130 signaling receptor–leukemia inhibitory factor (LIF), oncostatin M, interleukin 11, or interleukin 6. Recloning of blast colony cells indicated that the majority were progenitor cells committed exclusively to macrophage formation and responding selectively to proliferative stimulation by macrophage colony-stimulating factor. Reculture of blast colony cells initiated by FL plus LIF in cultures containing granulocyte/macrophage colony-stimulating factor plus tumor necrosis factor α indicated that at least some of the cells were capable of maturation to dendritic cells. The cells forming blast colonies in response to FL plus LIF were unrelated to those forming blast colonies in response to stimulation by stem cell factor and appear to be a distinct subset of mature hematopoietic stem cells.