Monday, March 26, 2012

Pain Research-Pubs Update

I am pleased to update you in recent publications and videos referencing use of our reagents for pain research. Check them out.
Andrew C. Eschenroeder, Allison A. Vestal-Laborde, Emilse S. Sanchez, Susan E. Robinson, Carmen Sato-Bigbee. Oligodendrocyte responses to buprenorphine uncover novel and opposing roles of μ-opioid- and nociceptin/orphanin FQ receptors in cell development: Implications for drug addiction treatment during pregnancy. Glia Volume 60, Issue 1, pages 125–136, January 2012....The MOR and NOP receptor antibodies were from Neuromics (Edina, MN) and used for immunocytochemistry (1:100)and western blotting (1:500)...

FiFigure. 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
In this study, researchers successfully transfect DRG cultures with IKAP-shRNA using our pn-Fect kit. The own regulation of IKAP in these cultures support findings that helped explain the potential pathology of Familial Dysautonomia (FD; Hereditary Sensory Autonomic Neuropathy; HSAN III): Hunnicutt BJ , Chaverra M , George L , Lefcort F , 2012 IKAP/Elp1 Is Required In Vivo for Neurogenesis and Neuronal Survival, but Not for Neural Crest Migration. PLoS ONE 7(2): e32050. doi:10.1371/journal.pone.0032050.

Related Links:
I will continue to post updates related to this important research area.

Sunday, March 18, 2012

Leptins and Obesity

Our Leptin and Leptin Receptor Markers have proven effective for researchers studying root causes of obesity. In this reference the authors show an interesting twist regarding the impact of endothial vs neuronal leptin signaling: Weihong Pan, Hung Hsuchou, Germaine G. Cornelissen-Guillaume, Bhavvani Jayaram, Yuping Wang, Hong Tu, Franz Halberg, Xiaojun Wu, Streamson C. Chua Jr., and Abba J. Kastin. Endothelial leptin receptor mutation provides partial resistance to diet-induced obesity. Published online before print February 2012, doi: 10.​1152/​japplphysiol.​00590.​2011.
...chicken anti-ObRb (1:100, Neuromics)...

Highlights: Leptin, a polypeptide hormone produced mainly by adipocytes, has diverse effects in both the brain and peripheral organs, including suppression of feeding. Other than mediating leptin transport across the blood-brain barrier, the role of the endothelial leptin receptor remains unclear. We recently generated a mutant mouse strain lacking endothelial leptin receptor signaling, and showed that there is an increased uptake of leptin by brain parenchyma after its delivery by in-situ brain perfusion. Here, we tested the hypothesis that endothelial leptin receptor mutation confers partial resistance to diet-induced obesity. These ELKO mice had similar body weight and percent fat as their wildtype littermates when fed with rodent chow, but blood concentrations of leptin were significantly elevated. In response to a high fat diet, wildtype mice had a greater gain of body weight and fat than ELKO mice . As shown by metabolic chamber measurement, the ELKO mice had higher oxygen consumption, carbon dioxide production, and heat dissipation, although food intake was similar to that of the wildtype mice and locomotor activity was even reduced. This indicates that the partial resistance to diet-induced obesity was mediated by higher metabolic activity in the ELKO mice. Since neuronal leptin receptor knockout mice show obesity and diabetes, the results suggest that endothelial leptin signaling shows opposite effects from that of neuronal leptin signaling, with a facilitatory role in diet-induced obesity.

Obesity is a growing health problem and will continue to drive up costs. Research like this could help find effective and log term solutions for helping with weight loss.

Thursday, March 08, 2012

P2X3 Receptors and Cool Science

Our P2X3 Receptor Antibodies are widely used and frequently published. This publication references use of our P2X3 Guinea Pig Antibody.

I like the "cool factor" in this study: Ji Z-G , Ito S , Honjoh T , Ohta H , Ishizuka T , et al. 2012 Light-evoked Somatosensory Perception of Transgenic Rats That Express Channelrhodopsin-2 in Dorsal Root Ganglion Cells. PLoS ONE 7(3): e32699. doi:10.1371/journal.pone.0032699.-"We have recently generated several transgenic lines of rat in which channelrhodopsin-2 (ChR2) transgene is driven by the Thy-1.2 promoter. In one of them, W-TChR2V4, some neurons were endowed with photosensitivity by the introduction of the ChR2 gene, coding an algal photoreceptor molecule. The DRG neurons expressing ChR2 were immunohistochemically identified using specific antibodies to the markers of mechanoreceptive or nociceptive neurons. Their peripheral nerve endings in the plantar skin as well as the central endings in the spinal cord were also examined. We identified that ChR2 is expressed in a certain population of large neurons in the DRG of W-TChR2V4. On the basis of their morphology and molecular markers, these neurons were classified as mechanoreceptive but not nociceptive. ChR2 was also distributed in their peripheral sensory nerve endings, some of which were closely associated with CK20-positive cells to form Merkel cell-neurite complexes or with S-100-positive cells to form structures like Meissner's corpuscles. These nerve endings are thus suggested to be involved in the sensing of touch. Each W-TChR2V4 rat showed a sensory-evoked behavior in response to blue LED flashes on the plantar skin. It is thus suggested that each rat acquired an unusual sensory modality of sensing blue light through the skin as touch-pressure. This light-evoked somatosensory perception should facilitate study of how the complex tactile sense emerges in the brain."

The researchers used Blue LED light to fire neurons involved somatosensory or tactile response!

Images. Distribution of ChR2V in the dorsal part of the spinal cord. A–C. Immunohistochemical localizationof ChR2V with the cell-type specific markers, NF200 (A), CGRP (B) or P2X3 (C). Scale bars indicate 40 µm.

Note that the receptors involved in Nociceptive Pain Sensing do not overlap with ChR2V. From this the authors conclude that ChR2V is involved in mechanoreception. This rat model should facilitate future study of how complex tactile perception, such as for texture, size and shape, is generated. We will keep you posted.

In the meantime check out our markers and antibodies for studying Neurotransmission and Synaptic Mechanisms.