Kv Channels and Acute to Chronic Pain Transistion

i-Fect ^TMis a Proven Tool for Gene Manipulation in Studying All Types of Pain

I previously posted on use of our i-Fect Transfection Kit to silence Kv Channels Receptors. This has enabled researchers to study the role of these receptors in vitro and in vivo (see:i-Fect™ Delivers Your siRNA Payload).

Sample Data

Figure: Figures. siRNA-mediated knockdown of Kv1.1 expression in thoracic DRG significantly increased gastric sensitivity in naive adult rats. (A) Western blots showed a significant decrease in Kv1.1 protein in thoracic DRG (T8–T12) after intrathecal treatment with Kv1.1 siRNA but not with control siRNA. siRNA treatment did not alter TrpV1 expression (n = 5 rats each; *P < .01 vs control siRNA). (B) Naive rats treated with Kv1.1 siRNA showed a significant increase in VMR to gastric distention (n = 5 rats each, compared with pretreatment baseline; *P < .05). (C) Treatment with control siRNA had no significant effect on gastric hypersensitivity. (D) Patch clamp recordings from freshly dissociated gastric DRG neurons from FD-like and PND 10 saline-treated littermate controls showed a significant decrease in rheobase in FD-like rats (*P < .05), and (E) a significant increase in the number of action potentials elicited by current injection at 3× the rheobase in gastric DRG neurons from FD-like rats (*P < .05). (F) Sample voltage vs time traces showing action potentials evoked at ×1, ×2, and ×3 rheobase. The patch clamp data were obtained from 16 cells from 5 PND 10 saline control rats and 19 cells from 5 FD-like rats

I am pleased to share with you a new reference detailing how research use i-Fect to optimize and deliver euchromatic histone-lysine N-methyltransferase-2 (G9a) siRNA. This brings the number of publications referencing use of our Transfection Kits to over 45: Geoffroy Laumet, Judit Garriga, Shao-Rui Chen, Yuhao Zhang, De-Pei Li, Trevor M Smith, Yingchun Dong, Jaroslav Jelinek, Matteo Cesaroni, Jean-Pierre Issa & Hui-Lin Pan G9a is essential for epigenetic silencing of K+channel genes in acute-to-chronic pain transition. Nature Neuroscience (2015) doi:10.1038/nn.4165.

The authors report: "Selective knockout of the gene encoding G9a in DRG neurons completely blocked K+ channel silencing and chronic pain development after nerve injury. Remarkably, RNA sequencing analysis revealed that G9a inhibition not only reactivated 40 of 42 silenced genes associated with K+ channels but also normalized 638 genes down- or upregulated by nerve injury."

I will continue to post here new and unique solutions and related referencing for our Gene Expression Analysis Tools.

i-Fect™ Delivers you siRNA Payload

Delivering siRNA to Dorsal Root Ganglia to Silence K_V Receptors.

Our i-Fect transfection kits continue to be used to optimize delivery in vivo and into hard to transfect cells like primary neurons. In these 2 latest expamples, researchers use i-Fect to deliver siRNA to K_V Receptors in Rat DRGs. Knocking down these receptors enable the study of their role in pain modulation: John H. Winston, Sushil K. Sarna. Developmental Origins of Functional Dyspepsia-Like Gastric Hypersensitivity in Rats. Gastroenterology. Volume 144, Issue 3, March 2013, Pages 570–579.e3. dx.doi.org/10.1053/j.gastro.2012.11.001....intrathecal treatment, 2 μg of the appropriate siRNA was mixed (1:5 vol/vol) with i-Fect transfection reagent (Neuromics, Edina, MN); rats received 2 ug siRNA/10 uL/rat/injection...

Figures. siRNA-mediated knockdown of Kv1.1 expression in thoracic DRG significantly increased gastric sensitivity in naive adult rats. (A) Western blots showed a significant decrease in Kv1.1 protein in thoracic DRG (T8–T12) after intrathecal treatment with Kv1.1 siRNA but not with control siRNA. siRNA treatment did not alter TrpV1 expression (n = 5 rats each; *P < .01 vs control siRNA). (B) Naive rats treated with Kv1.1 siRNA showed a significant increase in VMR to gastric distention (n = 5 rats each, compared with pretreatment baseline; *P < .05). (C) Treatment with control siRNA had no significant effect on gastric hypersensitivity. (D) Patch clamp recordings from freshly dissociated gastric DRG neurons from FD-like and PND 10 saline-treated littermate controls showed a significant decrease in rheobase in FD-like rats (*P < .05), and (E) a significant increase in the number of action potentials elicited by current injection at 3× the rheobase in gastric DRG neurons from FD-like rats (*P < .05). (F) Sample voltage vs time traces showing action potentials evoked at ×1, ×2, and ×3 rheobase. The patch clamp data were obtained from 16 cells from 5 PND 10 saline control rats and 19 cells from 5 FD-like rats.
Tsantoulas C, Zhu L, Shaifta Y, Grist J, Ward JP, Raouf R, Michael GJ, McMahon SB. Sensory neuron downregulation of the Kv9.1 potassium channel subunit mediates neuropathic pain following nerve injury. J Neurosci. 2012 Nov 28;32(48):17502-13. doi: 10.1523/JNEUROSCI.3561-12.2012..."I'd just like to notify you about a recent paper from my team which utilised iFect for in vivo transfection of dorsal root ganglia." Dr. Christoforos Tsantoulas, University of Cambridge...i-Fect-siRNA-mediated knock-down of Kv9.1 in naive rats led to neuropathic pain behaviors...

These add to the many publications referencing use of i-Fect to deliver siRNA. Genes studied include:  DOR, hTERT, The β3 subunit of the Na+,K+-ATPase, rSNSR1, NTS1. NAV1.8, , RANK, Toll-Like Receptors, Kv Recptors, BDNF, Ret, TRPV1, Survivin, Flaviviruses, NOV, Troy β-arrestin, TRPV1 CAV1.2 TLR4 and ASIC.