Delivering siRNA in vivo

New Publications

Our i-Fect transfection kit was one of the first products. This has resulted in it being widely used and frequently published.

We kick off 2018 with some new publications. Here we feature a study where researchers use our kit to deliver G-protein-coupled receptor C (MrgprC) siRNA in vivo. This receptor is part of the TRPV1 pathway.

• Ying-jun Liu, Xiao-xi Lin, Jian-qiao Fang, and Fang Fang. Involvement of MrgprC in electroacupuncture analgesia for attenuating CFA-induced thermal hyperalgesia by suppressing the TRPV1 pathway. Pre-pub-full text PDF

Image: Expression of TRPV1 in rats treated with MrgrprC si RNA vs controls (C).

The others conclude that MrgprC expression is impacted by electroacupuncture and downregulates  TRPV1.  This is the mechanism that results in pain relief.

More iFect in-vivo

The parade of publications continues to grow.

Here researchers use our i-Fect^TM Transfection Kit for delivering sh-IRF3 in vivo: Rui Li, Li-guo Wang, Qi Wang, Zhi-hua Li, Ya-li Ma, Qing-Duo Guo. Silencing of IRF3 alleviates chronic neuropathic pain following chronic constriction injury. doi.org/10.1016/j.biopha.2017.01.085... The oligonucleotides for sh-IRF3 were: 5′-CACCGCGTCTAGGCTGGTGGTTATTCGAAAATAACCACCAGCCTAGACGC-3′ −3′. Then, 10 μg sh-IRF3 dissolved in 30 μl i-Fect transfection reagent (Neuromics, Edina, MN, USA) was administered intrathecally once daily for 7...

Fig. Down-regulation of IRF3 attenuated mechanical allodynia and thermal hyperalgesia in CCI rats. (A) The mRNA expression level of IRF3 in the DRG at postoperative day 7. (B) The protein expression level of IRF3 in the DRG at postoperative day 7. (C and D) PWT and PWL were measured 1 day before CCI and 1, 3, 7 and 14 days after intrathecal injection of sh-IRF3 or scramble.

Down-regulation of IRF3 inhibited the production of pro-inflammatory cytokines in the DRG of CCI rats.

These results indicated that IRF3 was involved in the development of neuropathic pain. Down-regulation of IRF3 attenuated neuropathic pain in CCI rats by inhibiting the activation of NF-κB signaling pathway, suggesting that IRF3 may be a novel and potential target for the treatment of neuropathic pain.

Silencing Cytokines in-vivo with i-Fect

Knocking Down Cytokines to Study Pain Response

We have many unique applications published by researchers using our Transfection Kits in vitro and in vivo. Here researchers simultaneously silence 3 immune/inflammatory response cytokines in vivo: Byung Moon Choi, Soo Han Lee, Sang Mee An, Do Yang Park, Gwan Woo Lee, and Gyu-Jeong Noh. The time-course and RNA interference of TNF-α, IL-6, and IL-1β expression on neuropathic pain induced by L5 spinal nerve transection in rats. Korean J Anesthesiol. 2015 Apr;68(2):159-169. English. Published online March 30, 2015. http://dx.doi.org/10.4097/kjae.2015.68.2.159.

Protocol: RNAs were administered as described, with modifications [11]. A cocktail of siRNA simultaneously targeting TNF-α (Silencer® Select siRNA; s128522, Ambion, Austin, TX, USA), IL-6 (Silencer® Select siRNA; s217844, Ambion, Austin, TX, USA) and IL-1b (Silencer® Select siRNA; s127941, Ambion, Austin, TX, USA), as well as a control siRNA (Silencer® Negative Control #1 siRNA; Cat #4635, Ambion, Austin, TX, USA), were prepared immediately prior to administration by mixing the RNA (200 µM) with the transfection reagent, i-Fect™ (Neuromics, Minneapolis, MN, USA), in a ratio of 1 : 5 (w : v). At this ratio, the final RNA/lipid complex concentration was 2 µg in 5 µl for each cytokine siRNA and 6 µg in 15 µl for the control siRNA. The cytokine siRNAs were combined and they and the control siRNA (15 µl each) were delivered to the lumbar region of the spinal cord via the intrathecal catheters. Injections were given daily on 5 consecutive days (-1, 0, 1, 2, 3 d after L5 SNT.

The changes in mechanically induced allodynia and hyperalgesia in the rats surviving for 6 d after SNT are shown in figure. Allodynia and hyperalgesia were lower in the COCK group than in the CON group by 2 d after SNT (P < 0.05) and the difference was maintained for the duration of the experiment.

Figure: The time course of mechanical allodynia (A) and hyperalgesia (B) in the ipsilateral hind paw of rats undergoing L5 spinal nerve transection (SNT) after the administration of control siRNA (CON group) or a cocktail of small interfering RNAs (siRNA) targeting TNF-α, IL-6 and IL1-β (COCK group). The data on the rats surviving for 6 d after SNT are expressed as mean ± SE. -1: 1 d prior to SNT, 0: the day of L5 SNT, 1, 2, 4 and 6: 1, 2, 4 and 6 d after L5 SNT. *P < 0.05 vs. CON group at each time point. MPE: maximal possible effect. The cut-off values for mechanical allodynia and hyperalgesia are 30 g and 250 g, respectively.

We will continue to post new applications and methods published by researchers using our Transfection Kits.

Silencing NOV in vivo using i-Fect

Implications for Treating Neuropathic or Inflammatory Pain


It has been a awhile since I posted results here for researchers using Neuromics' i-Fect ™ siRNA Transfection Kits. Over the past months, we have enjoyed more growth in use of these kits so I anticipate more positive results to come.

Inflammation plays and evil role in Neuropathic Pain. Sustained neuroinflammation cased by  release of pro-inflammatory cytokines and chemokines (including TNF-α, IL-1β, IL-6 and CCL2). Emerging studies have established that the extracellular matrix (ECM) components, particularly matrix metalloproteinases (MMPs) actively participate in the generation and maintenance of pain.
In this study, investigators show how modulating expression of nephroblastoma overexpressed gene (NOV) can mitigate expression of the MMPs and thus regulate Pain: Lara Kular, Cyril Rivat, Brigitte Lelongt, Claire Calmel, Maryvonne Laurent, Michel Pohl, Patrick Kitabgi, Stephane Melik-Parsadaniantz and Cecile Martinerie. NOV/CCN3 attenuates inflammatory pain through regulation of matrix metalloproteinases-2 and -9. Journal of Neuroinflammation 2012, 9:36 doi:10.1186/1742-2094-9-36.
Results:  NOV was expressed in neurons of both dorsal root ganglia (DRG) and dorsal horn of the spinal cord (DHSC). After intraplantar CFA injection, NOV levels were transiently and persistently down-regulated in the DRG and DHSC, respectively, occurring at the maintenance phase of pain (15 days). NOV-reduced expression was restored after treatment of CFA rats with dexamethasone. In vitro, results based on cultured DRG neurons showed that siRNA-mediated inhibition of NOV enhanced IL-1beta- and TNF-alpha-induced MMP-2, MMP-9 and CCL2 expression whereas NOV addition inhibited TNF-alpha-induced MMP-9 expression through beta1 integrin engagement. In vivo, the intrathecal delivery of MMP-9 inhibitor attenuated mechanical allodynia of CFA rats. Importantly, intrathecal administration of NOV siRNA specifically led to an up-regulation of MMP-9 in the DRG and MMP-2 in the DHSC concomitant with increased mechanical allodynia. Finally, NOV intrathecal treatment specifically abolished the induction of MMP-9 in the DRG and, MMP-9 and MMP-2 in the DHSC of CFA rats. This inhibitory effect on MMP is associated with reduced mechanical allodynia.
Conclusions:  This study identifies NOV as a new actor against inflammatory pain through regulation of MMPs thus uncovering NOV as an attractive candidate for therapeutic improvement in pain relief.

Figure 9. Effect of in vivo endogenous NOV inhibition on MMP-2/-9 expression and mechanical allodynia. In CFA rats, NOV-specific siRNA (2 μg) or control non-silencing siRNA (Ctr) were delivered intrathecally (i.t) daily for 3 consecutive days. (A) NOV protein levels in DHSC. Representative western blot (left panel) and quantification of protein levels normalized to GAPDH (right panel) (**P <0.01, siNOV versus Ctr, n = 6) (B, C) Levels of MMP-9 and MMP-2 mRNA in DRG (B) and DHSC. (C) Transcript levels were quantified by RT-qPCR and values were normalized to rat S26 mRNA level. Data represent the mean value ± SEM of two independent experiments realized with three rats per condition (*P <0.05 siNOV versus Ctr). (D) Representative gelatin zymograph showing MMP-9 and MMP-2 activities in DRG (left panel) and quantification of MMP-2 and MMP-9 gelatinolytic bands (right panel). Data represent the mean ± SEM of six rats per group (**P <0.01 siNOV versus Ctr). (E) Paw withdrawal threshold (g) of CFA rats intrathecally injected with NOV-specific siRNA or control siRNA evaluated using the von Frey test. Data represent the mean ± SEM of eight rats per group (*P <0.05 siNOV- versus Ctr-treated rats), BL: baseline In order to test whether endogenously produced NOV could modulate inflammatory pain, we evaluated the mechanical allodynia of CFA rats treated with NOV. As shown in Figure 9E, intrathecal delivery of siNOV resulted in a significant increase of mechanical allodynia compared to rats injected with control siRNA (*P <0.05, n = 8). These data strongly suggest that endogenously produced NOV influences pain intensity and further support the hypothesis that NOV downregulation could participate in pain processes through
upregulation of MMP-2 and MMP-9.

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