Differential mechanisms of cold sensitivity in mouse trigeminal and vagal ganglion neurons

Mapping Intimacies ◽

10.1101/2021.08.05.455314 ◽

2021 ◽

Author(s):

Katharina Gers-Barlag ◽

Pablo Hernández-Ortego ◽

Eva Quintero ◽

Félix Viana

Keyword(s):

Cold Sensitivity ◽

Cold Temperatures ◽

Retrograde Labelling ◽

Critical Elements ◽

Thermally Driven ◽

Cold Sensitive ◽

Ganglion Neurons ◽

Vagal Ganglia

Thermal signals are critical elements in the operation of interoceptive and exteroceptive neural circuits, essential for triggering thermally-driven reflexes and conscious behaviors. A fraction of cutaneous and visceral sensory endings are activated by cold temperatures. Compared to somatic (DRG and TG) neurons, little is known about the mechanisms underlying cold sensitivity of visceral vagal neurons. We used pharmacological and genetic tools for a side-by-side characterization of cold-sensitive (CS) neurons in adult mouse trigeminal (TG) and vagal ganglia (VG). We found that CS neurons are more abundant in VG than in TG. In both ganglia, sensitivity to cold varied widely and was enhanced by the potassium channel blocker 4-AP. The majority of CS neurons in VG co-express TRPA1 markers and cold-evoked responses are severely blunted in Trpa1 KO mice, with little impact of TRPM8 deletion or pharmacological TRPM8 blockade. Consistent with these findings, the expression of TRPM8-positive neurons was low in VG and restricted to the rostral jugular ganglion. In vivo retrograde labelling of airway-innervating vagal neurons demonstrated their enhanced cold sensitivity and a higher expression of TRPA1 compared to neurons innervating the stomach wall. In contrast, the majority of CS TG neurons co-express TRPM8 markers and their cold sensitivity is reduced after TRPM8 deletion or blockade. However, pharmacological or genetic reduction of TRPA1 showed that these channels contribute significantly to their cold sensitivity in TG. In both ganglia, a fraction of CS neuron respond to cooling by a mechanism independent of TRPA1 or TRPM8 yet to be characterized.

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Characterization of Functional Vanilloid Receptors Expressed by Mast Cells

Blood ◽

10.1182/blood.v91.4.1332 ◽

1998 ◽

Vol 91 (4) ◽

pp. 1332-1340 ◽

Cited By ~ 143

Author(s):

Tamás Bı́ró ◽

Marcus Maurer ◽

Shayan Modarres ◽

Nancy E. Lewin ◽

Chaya Brodie ◽

...

Keyword(s):

Mast Cells ◽

Ruthenium Red ◽

Dorsal Root Ganglion Neurons ◽

Interleukin 4 ◽

Vanilloid Receptors ◽

45Ca Uptake ◽

Ganglion Neurons ◽

Type Receptor

Abstract Capsaicin and its ultrapotent analog resiniferatoxin (RTX) act through specific vanilloid receptors on sensory neurons. The C-type receptor is coupled to 45Ca uptake, whereas the R-type is detectable by [3H]RTX binding. We describe here specific vanilloid responses in murine mast cells (MCs). In the MC lines and in bone marrow-derived mast cells, capsaicin and RTX induced45Ca uptake similarly to that observed for cultured rat dorsal root ganglion neurons (DRGs). This response was antagonized by the antagonists capsazepine and ruthenium red. As in DRGs, pretreatment of MCs with capsaicin or RTX induced desensitization to subsequent stimulation of 45Ca uptake. The potency for desensitization by RTX in the MCs corresponded to that for 45Ca uptake, whereas in DRGs it occurred at significantly lower concentrations corresponding to that for the high-affinity [3H]RTX binding site. Consistent with this difference, in MCs we were unable to detect [3H]RTX binding. Vanilloids were noncytotoxic to the MCs, in contrast to the DRGs. Although vanilloids did not cause degranulation in MCs, in the P815 clone capsaicin evoked selective interleukin-4 release. We conclude that certain MCs possess vanilloid receptors, but only the C-type that functions as a channel. Our finding that MCs can respond directly to capsaicin necessitates a reevaluation of the in vivo pathway of inflammation in response to vanilloids.

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Sequential cold-sensitive mutations in Aspergillus fumigatus. III. Mechanism of cold sensitivity

Canadian Journal of Microbiology ◽

10.1139/m81-047 ◽

1981 ◽

Vol 27 (3) ◽

pp. 304-310 ◽

Cited By ~ 2

Author(s):

Anthony J. Arseneau ◽

Kenneth F. Gregory

Keyword(s):

Aspergillus Fumigatus ◽

Rna Synthesis ◽

Feedback Inhibition ◽

Ribosomal Subunit ◽

Cold Sensitivity ◽

Nonpermissive Temperature ◽

Cold Sensitive ◽

Ribosomal Rna Processing

The mechanism of cold sensitivity of Aspergillus fumigatus ON5, a 37 °C-sensitive mutant derived from A. fumigatus I-21 (ATCC 32722) by five sequential mutations, was investigated. The rate of in vivo protein synthesis by ON5 was not affected for 2 h following a shift from 45 to 34 °C, but the rate of in vivo RNA synthesis dropped almost immediately. The RNA polymerases of ON5 possessed wild-type activity in vitro at a nonpermissive temperature (34 °C) indicating that the reduction in the rate of in vivo RNA synthesis did not result from cold sensitivity in transcription, but was possibly a result of rapid feedback inhibition of transcription. Mutant ON5 was not able to produce ribosomes at a nonpermissive temperature as evidenced by the fact that no 3H-labelled amino acids were incorporated into the monosome, large ribosomal subunit, or small ribosomal subunit at 34 °C. Ribosomal subunit assembly or ribosomal RNA processing appears, therefore, to be the cold-sensitive cellular function in ON5.

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Pleiotropic Defects Caused by Loss of the Proteasome-Interacting Factors Rad23 and Rpn10 of Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/153.1.69 ◽

1999 ◽

Vol 153 (1) ◽

pp. 69-79

Author(s):

David Lambertson ◽

Li Chen ◽

Kiran Madura

Keyword(s):

Slow Growth ◽

26S Proteasome ◽

Cold Sensitivity ◽

Genetic Studies ◽

Single Mutant ◽

M Phase ◽

Cold Sensitive ◽

Increased Sensitivity

Abstract Rad23 is a member of a novel class of proteins that contain unprocessed ubiquitin-like (UbL) domains. We showed recently that a small fraction of Rad23 can form an interaction with the 26S proteasome. Similarly, a small fraction of Rpn10 is a component of the proteasome. Rpn10 can bind multiubiquitin chains in vitro, but genetic studies have not clarified its role in vivo. We report here that the loss of both Rad23 and Rpn10 results in pleiotropic defects that are not observed in either single mutant. rad23Δ rpn10Δ displays slow growth, cold sensitivity, and a pronounced G2/M phase delay, implicating overlapping roles for Rad23 and Rpn10. Although rad23Δ rpn10Δ displays similar sensitivity to DNA damage as a rad23Δ single mutant, deletion of RAD23 in rpn10Δ significantly increased sensitivity to canavanine, a phenotype associated with an rpn10Δ single mutant. A mutant Rad23 that is unable to bind the proteasome (ΔUbLrad23) does not suppress the canavanine or cold-sensitive defects of rad23Δ rpn10Δ, demonstrating that Rad23/proteasome interaction is related to these effects. Finally, the accumulation of multiubiquitinated proteins and the stabilization of a specific proteolytic substrate in rad23Δ rpn10Δ suggest that proteasome function is altered.

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Spb1p Is a Yeast Nucleolar Protein Associated with Nop1p and Nop58p That Is Able To BindS-Adenosyl-l-Methionine In Vitro

Molecular and Cellular Biology ◽

10.1128/mcb.20.4.1370-1381.2000 ◽

2000 ◽

Vol 20 (4) ◽

pp. 1370-1381 ◽

Cited By ~ 38

Author(s):

Lionel Pintard ◽

Dieter Kressler ◽

Bruno Lapeyre

Keyword(s):

Ribosomal Subunit ◽

Restrictive Temperature ◽

Protein Sequence Analysis ◽

Nucleolar Proteins ◽

Cold Sensitive ◽

Binding Protein Gene ◽

Sensitive Allele

ABSTRACT We present here the characterization of SPB1, an essential yeast gene that is required for ribosome synthesis. A cold-sensitive allele for that gene (referred to here asspb1-1) had been previously isolated as a suppressor of a mutation affecting the poly(A)-binding protein gene (PAB1) and a thermosensitive allele (referred to here asspb1-2) was isolated in a search for essential genes required for gene silencing in Saccharomyces cerevisiae. The two mutants are able to suppress the deletion of PAB1, and they both present a strong reduction in their 60S ribosomal subunit content. In an spb1-2 strain grown at the restrictive temperature, processing of the 27S pre-rRNA into mature 25S rRNA and 5.8S is completely abolished and production of mature 18S is reduced, while the abnormal 23S species is accumulated. Spb1p is a 96.5-kDa protein that is localized to the nucleolus. Coimmunoprecipitation experiments show that Spb1p is associated in vivo with the nucleolar proteins Nop1p and Nop5/58p. Protein sequence analysis reveals that Spb1p possesses a putative S-adenosyl-l-methionine (AdoMet)-binding domain, which is common to the AdoMet-dependent methyltransferases. We show here that Spb1p is able to bind [3H]AdoMet in vitro, suggesting that it is a novel methylase, whose possible substrates will be discussed.

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TRPM8 mRNA Is Expressed in a Subset of Cold-Responsive Trigeminal Neurons From Rat

Journal of Neurophysiology ◽

10.1152/jn.00843.2002 ◽

2003 ◽

Vol 90 (1) ◽

pp. 515-520 ◽

Cited By ~ 114

Author(s):

Michele L. Nealen ◽

Michael S. Gold ◽

Paul D. Thut ◽

Michael J. Caterina

Keyword(s):

Cold Temperatures ◽

Trigeminal Neurons ◽

Cold Receptors ◽

Electrophysiological Studies ◽

Ionic Mechanisms ◽

Cold Sensitive ◽

Low Threshold ◽

Ion Channel Proteins ◽

Trigeminal Ganglion Neurons ◽

Ganglion Neurons

Recent electrophysiological studies of cultured dorsal root and trigeminal ganglion neurons have suggested that multiple ionic mechanisms underlie the peripheral detection of cold temperatures. Several candidate “cold receptors,” all of them ion channel proteins, have been implicated in this process. One of the most promising candidates is TRPM8, a nonselective cationic channel expressed in a subpopulation of sensory neurons that is activated both by decreases in temperature and the cooling compound menthol. However, evidence for the expression of TRPM8 in functionally defined cold-sensitive neurons has been lacking. Here, we combine fluorometric calcium imaging of cultured rat trigeminal neurons with single-cell RT-PCR to demonstrate that there are distinct subpopulations of cold responsive neurons and that TRPM8 likely contributes to cold transduction in one of them. TRPM8 is preferentially expressed within a subset of rapidly responsive, low-threshold (approximately 30°C), cold-sensitive neurons. A distinct class of slowly responsive cold-sensitive neurons that is activated at lower temperatures (approximately 20°C) generally lacks detectable TRPM8 mRNA. Together with previous findings, our data support the notion that cold responsive neurons are functionally heterogeneous.

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Functional characterization of human brown adipose tissue metabolism

Biochemical Journal ◽

10.1042/bcj20190464 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1261-1286 ◽

Cited By ~ 3

Author(s):

Marie Anne Richard ◽

Hannah Pallubinsky ◽

Denis P. Blondin

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Functional Characterization ◽

Human Infants ◽

Positron Emission ◽

Brown Adipose ◽

Treatment Of Obesity ◽

And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

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In vivo characterization of plaque composition in late Cardiac Allograft Vasculopathy

European Journal of Heart Failure Supplements ◽

10.1016/s1567-4215(08)60545-7 ◽

2008 ◽

Vol 7 ◽

pp. 196-196

Author(s):

T OBERNDORFER ◽

M FRICK ◽

J DOERLER ◽

C MUSSNER ◽

D HOEFER ◽

...

Keyword(s):

Cardiac Allograft Vasculopathy ◽

Cardiac Allograft ◽

Plaque Composition ◽

Allograft Vasculopathy ◽

In Vivo Characterization

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Comparison of Immunological and Functional Assays for Measurement of Soluble Fibrin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649796 ◽

1995 ◽

Vol 74 (02) ◽

pp. 673-679 ◽

Cited By ~ 21

Author(s):

C E Dempfle ◽

S A Pfitzner ◽

M Dollman ◽

K Huck ◽

G Stehle ◽

...

Keyword(s):

Venous Thrombosis ◽

Low Grade ◽

Plasma Samples ◽

Normal Range ◽

Soluble Fibrin ◽

Discriminating Power ◽

Fibrin Monomer ◽

Cerebral Ischemic

SummaryVarious assays have been developed for quantitation of soluble fibrin or fibrin monomer in clinical plasma samples, since this parameter directly reflects in vivo thrombin action on fibrinogen. Using plasma samples from healthy blood donors, patients with cerebral ischemic insult, patients with septicemia, and patients with venous thrombosis, we compared two immunologic tests using monoclonal antibodies against fibrin-specific neo-epitopes, and two functional tests based on the cofactor activity of soluble fibrin complexes in tPA-induced plasminogen activation. Test A (Enzymun®-Test FM) showed the best discriminating power among normal range and pathological samples. Test B (Fibrinostika® soluble fibrin) clearly separated normal range from pathological samples, but failed to discriminate among samples from patients with low grade coagulation activation in septicemia, and massive activation in venous thrombosis. Functional test C (Fibrin monomer test Behring) displayed good discriminating power between normal and pathological range samples, and correlated with test A (r = 0.61), whereas assay D (Coa-Set® Fibrin monomer) showed little discriminating power at values below 10 μg/ml and little correlation with other assays. Standardization of assays will require further characterization of analytes detected.

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