TRPV1, Gut Inflammation and Pain

"Where there's smoke there's fire" or in this study, where there's inflammation there is pain: Robert P. Watson, Elliot Lilley, Moh Panesar, Gurdip Bhalay, Steven Langridge, Shin-Shay Tian, Conor McClenaghan, Anna Ropenga, Fanning Zeng, Mark S. Nash. Increased prokineticin 2 expression in gut inflammation: role in visceral pain and intestinal ion transport. Neurogastroenterology & Motility. Volume 24, Issue 1, pages 65–e12, January 2012....Formalin-fixed, wax-embedded tissues with no overt signs of pathology were purchased from Asterand (Detroit, MI, USA); informed consent had been sought and received from all donors. All tissues were used in accordance with the Human Tissue Act 2004 (UK)...guinea pig anti-TRPV1 antibody (GP14100 – Neuromics, Edina, MN, USA)...

Images: expression of prokineticin receptors in human and rat tissues. (A) Immunohistochemical analysis of PKR1 expression in the myenteric and submucosal ganglia of human stomach, ileum, and colon. Pkr1 (B) and Pkr2(C) expression in a range of human tissues determined using qRT-PCR. (D, E) Immunohistochemical of PKR1 distribution in rat DRG showing an absence of expression in large diameter, NF200 positive neurons (D), but co-expression with TRPV1 in presumptive nociceptive sensory neurons (E). (F) Distribution of Pkr2 mRNA by in situ hybridization in rat DRG. The IHC/ISH images shown are representative of the data obtained from n = 3 donors/animals.



Key Results Prok2 gene expression was up-regulated in biopsy samples from ulcerative colitis patients, and similar elevations were observed in rodent models of inflammatory colitis. Prokineticin receptor 1 (PKR1) was localized to the enteric neurons and extrinsic sensory neurons, whereas Pkr2 expression was restricted to sensory ganglia. In rats, PROK2-increased intracellular calcium levels in cultured enteric and dorsal root ganglia neurons, which was blocked by Compound 3. Moreover, PROK2 acting at prokineticin receptors stimulated intrinsic neuronally mediated ion transport in rat ileal mucosa. In vivo, Compound 3 reversed intracolonic mustard oil-induced referred allodynia and TNBS-induced visceral hypersensitivity, but not non-inflammatory, stress-induced visceral pain.

Check out our Pain and Inflammation Research Antibodies.

TRPV1s in Action

Our TRPV1s continue to be widely used and published. This recent publication features use out TRPV1-C guinea pig polyclonal for immunohistochemistry and TRPV1-mouse specific for Western Blotting: Sarah E. Canetta, Edlira Luca, Elyse Pertot, Lorna W. Role, David A. Talmage. Type III Nrg1 Back Signaling Enhances Functional TRPV1 along Sensory Axons Contributing to Basal and Inflammatory Thermal Pain Sensation. PLoS ONE 6(9): e25108. doi:10.1371/journal.pone.0025108...IHC: TRPV1 (guinea pig, 1:1000, GP14100 Neuromics); WB: TRPV1 (rabbit, 1:1000, RA14113 Neuromics).

Figure. Sensory axons, but not soma, from Type III Nrg1+/− mice show reduced capsaicin responsiveness compared to axons from WT mice. (A) Representative traces of intracellular calcium along sensory axons in response to 1 µM capsaicin or 56 mM KCl. The change in intracellular calcium from baseline over time ([(F−F0)/F0]*100) is shown for WT (left) and Type III Nrg1+/− (right) axons. Hatched diagonal lines indicate where the time course was non-continuous. (B) Quantification of the maximum change in intracellular calcium in response to application of 1 µM capsaicin or 56 mM KCl by genotype. Averages of 5 animals per genotype were compared using a Student's t-test. Type III Nrg1+/− axons showed a significantly decreased response to capsaicin (p<0.05), but not to KCl, relative to WTs. Graph shows mean±SEM. (C) Type III Nrg1+/− sensory soma show normal response to capsaicin. Quantification of maximal change in fluorescence from baseline ([(F−F0)/F0]*100) in WT or Type III Nrg1+/− sensory neuron soma in response to 1 µM capsaicin or 56 mM KCl. Average responses from 4 WT and 4 Type III Nrg1+/− animals to application of capsaicin or KCl were compared by genotype using a Student's t-test. There was no statistically significant difference between genotypes. Graphs show mean±SEM. (D) Type III Nrg1 (green) and TRPV1 (red) are co-expressed along P21 WT cultured sensory neuron axons identified with a pan-axonal (PA) marker (blue). White arrows indicate examples where Type III Nrg1 and TRPV1 are in close proximity. Scale bar equals 10 µm. (E) P21 WT and Type III Nrg1+/− sensory neuron cultures have equivalent levels of total TRPV1 protein. Total TRPV1 protein measurement by immunoblot. The 95 kD TRPV1 band and the 35 kD GAPDH band are shown from a representative experiment comparing protein from P21 WT and Type III Nrg1+/− cultures. Quantification of fold change in intensity of TRPV1:GAPDH normalized to WT average. There was no statistically significant change in the ratio of TRPV1 to GAPDH between genotypes (WT, Type III Nrg1+/−, n = 3 animals). Genotype comparisons were made using a Student's t-test. Graph shows mean±SEM. doi:10.1371/journal.pone.0025108.g004
All TRPV1 Publications.

Blood Pressure, Transient Receptor Potential Vanilloid 1 Receptors and Baroreceptors

Dr. Dr. Hui-Lin Pan (Department of Anesthesiology) and his team at M. D. Anderson Cancer Center has been a loyal user of our TRPV1 (VR1) since the early days of Neuromics' existence. We appreciate their continuing to use our reagent in their research.

Here's yet another publication:

Hao Sun, De-Pei Li, Shao-Rui Chen, Walter N. Hittelman and Hui-Lin Pan. Sensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on Baroreceptors. doi:10.1124/jpet.109.160473

...VR1 C-terminus (TRPV1), dilution 1:1000, Neuromics...

Related Reagents:
All TRP Antibodies
Pain and Inflammation Research Antibodies
Neurotransmission -Neurotransmission Research Antibody Categories

TRPV1 Antibodies in Action

We would like to thank Dr. Fletcher White, LUMC, for Sharing this data with us:

Images: The CCR2 chemokine receptor colocalized with IB4 and TRPV1, markers of nociceptive neurons, after injury. A) Many lumbar DRG neurons in vehicle-treated rat sensory neurons were positive for IB4, a neuronal phenotype that distinguishes some C-fiber nociceptors (red cells), however there was no expression of the CCR2 protein. B) After perineural gp120/hCD4 treatment, CCR2 protein expression (green cells) was upregulated, and co-localized with IB4. C) Both gp120/hCD4 and ddC treatment resulted in an upregulation of CCR2 expression (green cells) in many small and medium diameter neurons. Again, CCR2 co-localized in a number of IB4 positive cells. D) The TRPV1 channel is present on many nociceptive neurons and is involved in the neuropathic pain mechanism. Under normal conditions, TRPV1 was expressed in neurons (red cells). E) After gp120/hCD4 treatment, CCR2 expression is upregulated (green cells) and colocalized with TRPV1. F) After the combination of gp120/hCD4 and ddC treatments, again CCR2 was upregulated to a similar degree as gp120/hCD4 treatment alone and exhibited some colocalizations with TRPV1.
Scale Bar: 100um.

We would also like to share recent publications referencing our TRPVs:

Hao Sun, De-Pei Li, Shao-Rui Chen, Walter Hittelman, and Hui-Lin PanSensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on BaroreceptorsJ. Pharmacol. Exp. Ther., Sep 2009; doi:10.1124/jpet.109.160473 ......guinea pig anti-TRPV1, dilution 1:1000, Neuromics, Minneapolis, MN) and secondary antibody...guinea pig anti-VR1 C-terminus (TRPV1), dilution 1:1000,Neuromics; and rabbit anti-NF200, dilution 1:100...guinea pig anti-TRPV1, dilution 1:1000, Neuromics) for 2 hr at room temperature and

overnight......Kenjiro Matsumoto, Emi Kurosawa, Hiroyuki Terui, Takuji Hosoya, Kimihito Tashima, Toshihiko Murayama, John V. Priestley, and Syunji HorieLocalization of TRPV1 and contractile effect of capsaicin in mouse large intestine: high abundance and sensitivity in rectum and distal colonAm J Physiol Gastrointest Liver Physiol, Aug 2009; 297: G348 - G360. ......TRPV1 antibody (mouse TRPV1 C-terminus; Neuromics, Minneapolis, MN) were 1:60,000 for rectum...different anti-TRPV1 antibodies (1:60,000, Neuromics, and rat TRPV1 COOH-terminus, 1:1,000...experiments, the antibody (1:60,000; Neuromics) was preincubated with 10 uM of the corresponding......

Featured Reagents:
VR1 N-Terminus (TRPV1)
VR1 C-terminus (TRPV1)
VR1 C-Terminus (TRPV1) - mouse specific
Related Reagents
VR1 (TRPV1)-Goat
VR like-3 (TRPV3)
All TRPV (Vanilloid); TRPM; TRPA and TRPCs
Pain and Inflammation Antibodies

TRPV1 and Retinal Ganglion Cell Apoptosis

The publications referencing our TRPV (Vanilloid); TRPM; TRPA and TRPC Antibodies keep on coming.

In this February 2009 publication, Dr. David Calkins and his team at Vanderbilt demontrate that Retinal Ganglian Cells express the TRPV1 channel and that TRPV1 activation contributes to their death with exposure to hydrostatic pressure . We also demonstrated that activation of TRPV1 alone was sufficient to induce apoptosis of RGCs.

Rebecca M. Sappington, Tatiana Sidorova, Daniel J. Long, and David J. Calkins. TRPV1: Contribution to Retinal Ganglion Cell Apoptosis and Increased Intracellular Ca2+ with Exposure to Hydrostatic Pressure. Invest. Ophthalmol. Vis. Sci., Feb 2009; 50: 717 - 728.
...we used rabbit anti-mouse TRPV1 IgG (1:500; catalog number RA14113; Neuromics, Edina, MN) against the absolute C terminus of mouse TRPV1 (EDAEVFKDSMAPGEK)...

TRPV1 localization in RGCs of rat retina. (A) Immunocytochemical labeling for TRPV1 shows strong localization in the outer retina and in RGCs (large cell bodies); there is little or no label in smaller displaced amacrine cells of the GCL. Clear examples of amoeboid-shaped cell bodies of microglia cells are indicated (ovals). Right: Control section preabsorbed using the TRPV1 blocking peptide (+BP). (B) Confocal image stack through GCL and NFL showing labeling for TRPV1 in wholemount preparation counterlabeled with antibodies against heavy-chain neurofilaments that recognize broad-field RGCs (SMI32). Image shows punctate localization to dendrites (arrows) as well as intense label to cell bodies (brackets); smaller cell bodies with TRPV1 label are in the background. (C) Confocal image stack through GCL and NFL of peripheral retina shows TRPV1 in RGC cell bodies (bracket) and in small bundles of RGC axons (arrows). (D) Confocal stack from central retina shows TRPV1 in RGC cell bodies (bracket) and in axon bundles in the NFL as they course toward the optic nerve head. Amoeboid-shaped cell bodies of microglia are apparent (ovals). (E) Confocal image in single plane at GCL/NFL border shows Iba-1–labeled microglia processes colocalizing with TRPV1, as we previously demonstrated.51 TRPV1-label RGC cell bodies (brackets) and axons (arrows) are indicated for reference. (F) Immunocytochemical labeling demonstrates strong perinuclear and dendritic localization of TRPV1 in cultured RGCs counterstained with the nuclear label DAPI. Localization to dendritic processes and neurites (dashed circles) includes node-like clusters; right: these regions are shown at higher magnification. (G, top) Western blot against TRPV1 in brain and whole retina from adult rat shows band at expected molecular weight (arrowheads; 100–113 kDa). Retina demonstrates an additional band with a slightly lower molecular weight that probably corresponds to a different glycosylation state for this antibody.79 Bottom: Control Western blot with preabsorption of TRPV1 antibody using the blocking peptide prevents detection of both bands. ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer; NFL, nerve fiber layer.