TRPV1 and Osteoarthritis Related Pain

Our TRPV Antibodies are widely used and frequently published. Many of these feature TRPVs' role in nociceptive pain. Specifically they play important roles in the detection of noxious stimuli and inflammatory hyperalgesia.

TRPV1 has been implicated in OA pain, both in animal models and by the finding that TRPV1 genetic variants are associated with the risk of symptomatic knee OA in humans: S Kelly, R J Chapman, S Woodhams, D R Sagar, J Turner, J J Burston, C Bullock, K Paton, J Huang, A Wong, D F McWilliams, B N Okine, D A Barrett, G J Hathway, D A Walsh, V Chapman. Increased function of pronociceptive TRPV1 at the level of the joint in a rat model of osteoarthritis pain. Ann Rheum Dis doi:10.1136/annrheumdis-2013-203413.
Methods: Rat spinal cord sections from MIA- and saline-treated rats (n=5/group) (see online supplemental methods) were incubated with a polyclonal guinea pig anti-TRPV1 antibody (1 : 500, Neuromics, Edina, Minnesota, USA catalogue number GP14100) and then with Alexa 568-conjugated goat anti-guinea pig secondary antibody (1:300, Molecular Probes). TRPV1 immunostaining was visualised with a Leica DMRB/DM4000 B fluorescence microscope and images were acquired using Openlab software (PerkinElmer)...

Images: Transient receptor potential vanilloid 1 (TRPV1) immunoreactivity in the spinal cord. TRPV1 immunofluorescence detected in superficial dorsal horn (10× magnification) in rat lumbar (L3–L5) spinal cord at day 28 post-intra-articular injection of saline (A) or mono-iodoacetate (MIA) (B). Minimum and maximum brightness values were altered (32.01 min and 90.14 max) using Image J so as to highlight the area of TRPV1 positive staining. (C) Quantification of TRPV1 immunofluorescence in superficial dorsal horn of spinal cord taken from rats at 14 or 28 days following intra-articular injection of MIA and at day 28 following intra-articular injection of saline. Data are expressed as mean and SEM (n=5 per group).

Clinical trials of oral TRPV1 antagonists have been limited by on-target-induced hyperthermia. Here experimental evidence for increased functional role of TRPV1 at the level of the joint in a model of OA pain and the demonstration that blockade of joint TRPV1 ablates sensory afferent sensitization and pain behaviour support future targeted site-specific investigations of the therapeutic potential of TRPV1 for OA pain associated with synovitis. This could be good news for OA sufferers.

Teminally Differentiated Human Chondrocytes

Save 20% on New Chondrocytes through November 30, 2012

Certain customers tell me they purchase our UCB and eSC Derived Human Mesenchymal Stem Cells to grow and differentiate into Chondrocyte cultures for the study of joint disease.

Our goal is to save time and expense in the development of your cell based assays. We now offer these options:

Name	Catalog #	Type	Species	Applications	Size	Price
Native Human Chondrocytes-Pilot	SC00A7-100K	Primary Cells	H	Cell Assays	100,000 Cells	$245
Native Human Chondrocytes-HCS	SC00A7-500K	Primary Cells	H	Cell Assays	500,000 Cells	$449
Native Human Chondrocytes-HTS Pilot	SC00A7-4000K	Primary Cells	H	Cell Assays	4X1,000,000 Cells	$2,399
Native Human Chondrocytes-HTS	SC00A7-1000K	Primary Cells	H	Cell Assays	1,000,000 Cells	$799
Fluorescein Labeled Human Chondrocytes-Pilot	SC00A8-100K	Primary Cells	H	Cell Assays	100,000 Cells	$295
Fluorescein Labeled Human Chondrocytes-HCS	SC00A8-500K	Primary Cells	H	Cell Assays	500,000 Cells	$449
Fluorescein Labeled Human Chondrocytes-HTS Pilot	SC00A7-1000K	Primary Cells	H	Cell Assays	1,000,000 Cells	$799
Fluorescein Labeled Human Chondrocytes-HTS	SC00A7-4000K	Primary Cells	H	Cell Assays	4X1,000,000 Cells	$2,399
Rhodamine Labeled Human Chondrocytes-Pilot	SC00A9-100K	Primary Cells	H	Cell Assays	100,000 Cells	$295
Rhodamine Human Chondrocytes-HCS	SC00A9-500K	Primary Cells	H	Cell Assays	500,000 Cells	$449
Rhodamine Labeled Human Chondrocytes-HTS Pilot	SC00A9-1000K	Primary Cells	H	Cell Assays	1,000,000 Cells	$799
Rhodamine Labeled Human Chondrocytes-HTS	SC00A9-4000K	Primary Cells	H	Cell Assays	4X1,000,000 Cells	$2,399
Human Chondrocytes Media	SC00PC3-100	Cell Growth Media	H		100 ml 500 ml	$79 $199

Images: Chondrocyte cultures.


We plan on continuing to add new potent and pure primary cells to accelerate meaning results from basic disease research and drug discovery.

ASIC3 and Osteoarthritis

ASIC3 modulates pain and disease progression

Neuromics' foundation is built on providing reagents for pain researchers. I have posted the twists and turns via key publications and related data. Here's yet another success story with one of our Pain and Inflammation Research Antibodies.

Acid sensing ion channels (ASICs) are sodium-selective ion channels activated by low extracellular pH, and belong to the degenerin/epithelial Na+ channel superfamily. ASIC3  is the most sensitive to such a pH change [2,3], abundantly expressed in dorsal root ganglia (DRG) [4], and strongly correlated with pain. Here researchers show the role of ASIC3 in osteoarthritis: Masashi Izumi, Masahiko Ikeuchi, Qinghui Ji, Toshikazu Tani. Local ASIC3 modulates pain and disease progression in a rat model of osteoarthritis. Journal of Biomedical Science 2012, 19:77 doi:10.1186/1423-0127-19-77.
Highlights: OA was induced via intra-articular mono-iodoacetate (MIA) injection, and pain related behaviors were evaluated including weight bearing measured with an incapacitance tester and paw withdrawal threshold in a von Frey hair test. OA rats showed not only weight-bearing pain but also mechanical hyperalgesia outside the knee joint (secondary hyperalgesia). ASIC3 expression in knee joint afferents was significantly upregulated approximately twofold at Day 14. Continuous intra-articular injections of APETx2 inhibited weight distribution asymmetry and secondary hyperalgesia by attenuating ASIC3 upregulation in knee joint afferents. Histology of ipsilateral knee joint showed APETx2 worked chondroprotectively if administered in the early, but not late phase.

Images: Fast Blue labeling and immunohistochemistry staining for ASIC3 : (a-b) Naïve- model, (c-d) OA-model, (e-f) APETx2 administration to OA-model in early phase. Photos in each row are the same DRG. In (b),(d),(f), large arrows indicate Fast Blue labeled, ASIC3 immunoreactive (ASIC3-ir) DRG cells, while ASIC3-ir cells that were not labeled by Fast Blue are indicated by small arrowheads. More than 100 FB-labeled neurons were analyzed from 4 rats in each group. The percentage of ASIC3-ir knee joint afferents was 18 ± 3% (mean ± SD) in naïve models, 46 ± 4% in OA-models (p = 0.003), and 20 ± 5% in the early-phase APETx2 group (p = 0.006), respectively. Scale bar: 50 μm

Protocol: The [DRG] sections were blocked in 3% normal goat serum for 1 h, then incubated in primary antibody of ASIC3 (Neuromics; Edina, MN, GP 14015, 1:500) overnight in a humid chamber. The next day, the sections were incubated in the secondary antibody (Vector; Burlingame, CA, FI-7000, 1:500, FITC tagged) for 2 h. All antisera used were diluted in PBS containing 1% normal goat serum and 0.05% Triton X-100. Before, between, and after each incubation step, the sections were washed 3 times for 5 min in PBS. Finally, all sections were mounted with Vectashield (Vector, Burlingame, CA).
1. Waldmann R, Champigny G, Bassilana F, Heurteaux C, Lazdunski M: A proton-gated cation channel involved in acid-sensing. Nature 1997, 386:173–177. 2. Lingueglia E: Acid-sensing ion channels in sensory perception. J Biol Chem 2007, 282:17325–17329. note: see http://neuromics.net/weblog/post/tag/dr-eric-lingueglia/ for research using our siRNA transfectio reagent for ASIC3 gene expression analysis. 
3. Wemmie JA, Price MP, Welsh MJ: Acid-sensing ion channels: advances, questions and therapeutic opportunities. Trends Neurosci 2006, 29:578–586.
4. Voilley N, de Weille J, Mamet J, Lazdunski M: Nonsteroid anti-inflammatory drugs inhibit both the activity and the inflammation-induced expression of acid-sensing ion channels in nociceptors. J Neurosci 2001, 21:8026–8033.