Light-induction of endocannabinoids and activation of Drosophila TRPC channels

Drosophila phototransduction represents a classical model for signaling cascades that culminate with activation of TRP channels. TRP and TRPL are the canonical TRP (TRPC) channels, which are gated by light stimulation of rhodopsin and engagement of Gq and phospholipase Cβ (PLC). Despite decades of investigation, the mechanism of TRP activation in photoreceptor cells is unresolved. Here, using a combination of genetics, lipidomics and Ca2+ imaging, we found that light increased the levels of an abundant endocannabinoid, 2-linoleoyl glycerol (2-LG) in vivo. The elevation in 2-LG strictly depended on the PLC encoded by norpA. Moreover, this endocannabinoid upregulated TRPC-dependent Ca2+ influx in a heterologous expression system and in dissociated ommatidia from compound eyes. We propose that 2-LG is a physiologically relevant endocannabinoid that activates TRPC channels in photoreceptor cells.

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The wall-less bacterium Spiroplasma poulsonii builds a polymeric cytoskeleton composed of interacting MreB isoforms

10.1101/2021.06.08.447548 ◽

2021 ◽

Author(s):

Florent Masson ◽

Xavier Pierrat ◽

Bruno Lemaitre ◽

Alexandre Persat

Keyword(s):

Cell Wall ◽

Cell Shape ◽

Expression System ◽

Interaction Network ◽

High Concentration ◽

Heterologous Expression System ◽

Independent Manner ◽

Cell Wall Biogenesis ◽

Rigid Cell Wall

A rigid cell wall defines the morphology of most bacteria. MreB, a bacterial homologue of actin, plays a major role in coordinating cell wall biogenesis and defining cell shape. In contrast with most bacteria, the Mollicutes family is devoid of cell wall. As a consequence, many Mollicutes have undefined morphologies. Spiroplasma species are an exception as they robustly grow with a characteristic helical shape, but how they maintain their morphology remains unclear. Paradoxal to their lack of cell wall, the genome of Spiroplasma contains five homologues of MreB (SpMreBs). Since MreB is a homolog of actin and that short MreB filaments participate in its function, we hypothesize that SpMreBs form a polymeric cytoskeleton. Here, we investigate the function of SpMreB in forming a polymeric cytoskeleton by focusing on the Drosophila endosymbiont Spiroplasma poulsonii. We found that in vivo, Spiroplasma maintain a high concentration of all five MreB isoforms. By leveraging a heterologous expression system that bypasses the poor genetic tractability of Spiroplasma, we found that strong intracellular levels of SpMreb systematically produced polymeric filaments of various morphologies. Using co-immunoprecipitation and co-expression of fluorescent fusions, we characterized an interaction network between isoforms that regulate the filaments formation. Our results point to a sub-functionalization of each isoform which, when all combined in vivo, form a complex inner polymeric network that shapes the cell in a wall-independent manner. Our work therefore supports the hypothesis where MreB mechanically supports the cell membrane, thus forming a cytoskeleton.

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TNF-α increases protein content in C2C12and primary myotubes by enhancing protein translation via the TNF-R1, PI3K, and MEK

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00129.2007 ◽

2008 ◽

Vol 294 (2) ◽

pp. E241-E250 ◽

Cited By ~ 31

Author(s):

Isabelle Plaisance ◽

Christian Morandi ◽

Claire Murigande ◽

Marijke Brink

Keyword(s):

Physiological Function ◽

Biological Effects ◽

Protein Translation ◽

Signaling Cascades ◽

Downstream Effectors ◽

Tnf Α ◽

In Vivo Animal Models ◽

Growth Promoting ◽

Stimulation Of

Recent evidence supports that TNF-α, long considered a catabolic factor, may also have a physiological function in skeletal muscle. The catabolic view, mainly based on correlative studies in human and in vivo animal models, was challenged by experiments with myoblasts, in which TNF-α induced differentiation. The biological effects of TNF-α in differentiated muscle, however, remain poorly understood. In the present study, we tested whether TNF-α has growth-promoting effects in myotubes, and we characterized the mechanisms leading to these effects. Treatment of C2C12myotubes with TNF-α for 24 h increased protein synthesis (PS) and enhanced cellular dehydrogenase activity by 22 and 26%, respectively, without changing cell numbers. These effects were confirmed in myotubes differentiated from primary rat myoblasts. TNF-α activated two signaling cascades: 1) ERK1/2 and its target eIF4E and 2) Akt and its downstream effectors GSK-3, p70S6K, and 4E-BP1. TNF-α-induced phosphorylation of Akt, and ERK1/2 was inhibited by an antibody against TNF-α receptor 1 (TNF-R1). PD-98059 pretreatment abolished TNF-α-induced phosphorylation of ERK1/2 and eIF4E, whereas PS was only partially inhibited. LY-294002 completely abolished TNF-α-induced stimulation of PS as well as phosphorylation of Akt and its downstream targets GSK-3, p70S6K, and 4E-BP1. Rapamycin inhibited TNF-α-induced phosphorylation of the mTOR C1 target p70S6Kwithout altering TNF-α-induced PS and 4E-BP1 phosphorylation. In conclusion, our results provide evidence that TNF-α enhances PS in myotubes and that this is based on enhanced protein translation mediated by the TNF-R1 and PI3K-Akt and MEK-ERK signaling cascades.

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Diclofenac-induced stimulation of SMCT1 (SLC5A8) in a heterologous expression system: A RPE specific phenomenon

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2010.02.109 ◽

2010 ◽

Vol 394 (1) ◽

pp. 75-80 ◽

Cited By ~ 7

Author(s):

Sudha Ananth ◽

Lina Zhuang ◽

Elangovan Gopal ◽

Shiro Itagaki ◽

Babu Ellappan ◽

...

Keyword(s):

Heterologous Expression ◽

Expression System ◽

Heterologous Expression System ◽

System A ◽

Stimulation Of

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Einfluss der Rotlichtstimulation auf die Fruchtbarkeit von Ebersperma

Tierärztliche Praxis Ausgabe G Großtiere / Nutztiere ◽

10.1055/a-1004-9968 ◽

2019 ◽

Vol 47 (05) ◽

pp. 328-329

Keyword(s):

Artificial Insemination ◽

Red Light ◽

Light Stimulation ◽

Boar Semen ◽

Stimulation Of

Blanco Prieto O, Catalán J, Lleonart M et al. Red-light stimulation of boar semen prior to artificial insemination improves field fertility in farms: A worldwide survey. Reprod Dom Anim 2019; 54: 1145–1148 In der weltweiten Schweinezucht ist die künstliche Besamung (KB) mit flüssigkonserviertem Sperma die vorherrschende Methode in der Reproduktion. Aus diesem Grund spielt die Optimierung der KB und damit der Reproduktionsleistung eine wichtige wirtschaftliche Rolle. Mehreren Studien zufolge kann die Rotlichtstimulation mit verschiedenen Lichtquellen die Beweglichkeit und In-vitro-Fertilisationsfähigkeit der Spermien von Säugetieren verbessern. Bei Ebersperma ließ sich zeigen, dass eine LED-basierte Rotlichtstimulation die Befruchtungsfähigkeit in vivo erhöht. Andere Studien ergaben variable Effekte der Rotlichtstimulation auf die in vitro untersuchten Spermienqualitätsparameter. Ziel dieser Studie war daher zu überprüfen, ob die Rotlichtstimulation mit dem Gerät MaXipig® unmittelbar vor der KB die mit dem behandelten Ebersperma erzielte Reproduktionsleistung steigert.

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TRPC Channels—Insight from the Drosophila Light Sensitive Channels

The Oxford Handbook of Neuronal Ion Channels ◽

10.1093/oxfordhb/9780190669164.013.5 ◽

2018 ◽

Author(s):

Ben Katz ◽

William L. Pak ◽

Baruch Minke

Keyword(s):

Transient Receptor Potential ◽

Trp Channels ◽

Receptor Potential ◽

Photoreceptor Cells ◽

Scaffold Proteins ◽

Trpc Channels ◽

Constitutive Activity ◽

Cell Degeneration ◽

Evolutionarily Conserved ◽

Transient Receptor

The Drosophila Transient Receptor Potential (TRP) channel is the founding member of a large and diverse family of channel proteins. These channels are evolutionarily conserved from yeast to mammals and are found in many organisms and tissues. The TRP family is classified into seven subfamilies, while the most closely related to the Drosophila TRP are members of the TRPC (Canonical) subfamily. This review focuses on a comparison between properties of Drosophila TRP, discovered in the native photoreceptor cells, and that of mammalian TRPC channels. These properties include: (i) organization of TRP channels in multimolecular signaling complexes via PDZ-containing scaffold proteins, (ii) mutations causing constitutive activity of TRP channels and cell degeneration, (iii) regulation of TRP channels by phosphorylation, and (iv) hypoxia/anoxia-activation of TRP channels. Hence, we suggest that knowledge gained from studies of Drosophila may guide studies in mammals that attempt elucidating diverse types of diseases caused by TRPC channel malfunction.

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La3+ Alters the Response Properties of Neurons in the Mouse Primary Somatosensory Cortex to Low-Temperature Noxious Stimulation of the Dental Pulp

Biochemistry Insights ◽

10.4137/bci.s30752 ◽

2015 ◽

Vol 8s1 ◽

pp. BCI.S30752

Author(s):

Yanjiao Jin

Keyword(s):

Low Temperature ◽

Somatosensory Cortex ◽

Dental Pulp ◽

Trp Channels ◽

Dental Pain ◽

Primary Somatosensory Cortex ◽

Noxious Stimulation ◽

Response Properties ◽

Stimulation Of

Although dental pain is a serious health issue with high incidence among the human population, its cellular and molecular mechanisms are still unclear. Transient receptor potential (TRP) channels are assumed to be involved in the generation of dental pain. However, most of the studies were conducted with molecular biological or histological methods. In vivo functional studies on the role of TRP channels in the mechanisms of dental pain are lacking. This study uses in vivo cellular electrophysiological and neuropharmacological method to directly disclose the effect of LaCl3, a broad spectrum TRP channel blocker, on the response properties of neurons in the mouse primary somatosensory cortex to low-temperature noxious stimulation of the dental pulp. It was found that LaCl3 suppresses the high-firing-rate responses of all nociceptive neurons to noxious low-temperature stimulation and also inhibits the spontaneous activities in some nonnociceptive neurons. The effect of LaCl3 is reversible. Furthermore, this effect is persistent and stable unless LaCl3 is washed out. Washout of LaCl3 quickly revitalized the responsiveness of neurons to low-temperature noxious stimulation. This study adds direct evidence for the hypothesis that TRP channels are involved in the generation of dental pain and sensation. Blockade of TRP channels may provide a novel therapeutic treatment for dental pain.

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Stimulation of ovarian progesterone secretion by oxytocin in vivo

Acta Endocrinologica ◽

10.1530/acta.0.117s199-a ◽

1988 ◽

Vol 117 (4_Suppl) ◽

pp. S199-S200

Author(s):

E. DIETRICH ◽

K. RENTELMANN ◽

W. WUTTKE

Keyword(s):

Progesterone Secretion ◽

Stimulation Of

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Faculty Opinions recommendation of Direct CD1d-mediated stimulation of APC IL-12 production and protective immune response to virus infection in vivo.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1474957.1424054 ◽

2010 ◽

Author(s):

Randy Brutkiewicz

Keyword(s):

Immune Response ◽

Virus Infection ◽

Protective Immune Response ◽

Stimulation Of

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Non-Viral Vectors for Gene Delivery

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681208666180110154233 ◽

2018 ◽

Vol 9 (1) ◽

pp. 4-11 ◽

Cited By ~ 5

Author(s):

Aparna Bansal ◽

Himanshu

Keyword(s):

Gene Therapy ◽

Viral Vectors ◽

Transfection Efficiency ◽

Gene Transfection ◽

Expression System ◽

Target Cells ◽

Specific Expression ◽

Naked Dna

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

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