NF-KappaB Pathway Is Involved in Bone Marrow Stromal Cell-Produced Pain Relief

Abstract

Bone marrow stromal cells (BMSCs) produce long-lasting attenuation of pain hypersensitivity. This effect involves BMSC’s ability to interact with the immune system and activation of the endogenous opioid receptors in the pain modulatory circuitry. The nuclear factor kappa B (NF-κB) protein complex is a key transcription factor that regulates gene expression involved in immunity. We tested the hypothesis that the NF-κB signaling plays a role in BMSC-induced pain relief. We focused on the rostral ventromedial medulla (RVM), a key structure in the descending pain modulatory pathway, that has been shown to play an important role in BMSC-produced antihyperalgesia. In Sprague-Dawley rats with a ligation injury of the masseter muscle tendon (TL), BMSCs (1.5 M/rat) from donor rats were infused i.v. at 1 week post-TL. P65 exhibited predominant neuronal localization in the RVM with scattered distribution in glial cells. At 1 week, but not 8 weeks after BMSC infusion, western blot and immunostaining showed that p65 of NF-κB was significantly increased in the RVM. Given that chemokine signaling is critical to BMSCs’ pain-relieving effect, we further evaluated a role of chemokine signaling in p65 upregulation. Prior to infusion of BMSCs, we transduced BMSCs with Ccl4 shRNA, incubated BMSCs with RS 102895, a CCR2b antagonist, or maraviroc, a CCR5 antagonist. The antagonism of chemokines significantly reduced BMSC-induced upregulation of p65, suggesting that upregulation of p65 was related to BMSCs’ pain-relieving effect. We then tested the effect of a selective NF-κB activation inhibitor, BAY 11-7082. The mechanical hyperalgesia of the rat was assessed with the von Frey method. In the pre-treatment experiment, BAY 11-7082 (2.5 and 25 pmol) was injected into the RVM at 2 h prior to BMSC infusion. Pretreatment with BAY 11-7082 attenuated BMSCs’ antihyperalgesia, but post-treatment at 5 weeks post-BMSC was not effective. On the contrary, in TL rats receiving BAY 11-7082 without BMSCs, TL-induced hyperalgesia was attenuated, consistent with dual roles of NF-κB in pain hypersensitivity and BMSC-produced pain relief. These results indicate that the NF-κB signaling pathway in the descending circuitry is involved in initiation of BMSC-produced behavioral antihyperalgesia.

Stem Cells from Human Exfoliated Deciduous Teeth Attenuate Trigeminal Neuralgia in Rats

“…For example, in sciatic nerve CCI model mice [ 22 , 33 ], intrathecal BMSCs exerted a persistent analgesic effect through the release of the anti-inflammatory growth factor transforming growth factor beta, which inhibited CCI-induced spinal neuroinflammation, downregulated TNF- α expression, and modulated excitatory synaptic transmission in spinal cord and dorsal root ganglion neurons [ 22 , 33 ]. Nuclear factor kappa B (NF- κ B) signaling plays a key role in BMSC-induced antihyperalgesia in rat models of persistent pain and spinal cord injury [ 34 , 35 ]. In spinal cord injury rats, BMSCs downregulated phosphorylated NF- κ B P65 subunit and decreased other proinflammatory factors, such as TNF- α and IL-1 β [ 35 ].…”

The negative charge of the 343 site is essential for maintaining physiological functions of CXCR4

“…Cells were fixed with 4% paraformaldehyde for 10 min at room temperature as described [ 37 ]. Immunostaining of p65 was done as described above [ 38 ]. Secondary, AlexaFluor 647-conjugated donkey anti-goat antibody was used at a concentration of 1:1000 (Thermofisher, USA) for 90 min.…”

Voluntary biting behavior as a functional measure of orofacial pain in mice

“…We finally verified whether the bite force measure could be used to detect pain-relief. We have shown that transplantation of BMSCs produces long-lasting pain relief in TL rats [17][18][19][20]. Since BMSCs are able to avoid immune rejection likely due to a lack of major histocompatibility complex class II molecules and co-stimulatory surface markers for T-cell activation [30], we infused rat BMSCs to mice.…”

“…Transplantation of human or rat BMSCs produces long-term attenuation of hyperalgesia/allodynia (antihyperalgesia) in rodents [17,59]. Assessed with the von Frey method and CPA behavioral test, we have shown previously that TL-induced pain hypersensitivity was attenuated by BMSCs [17][18][19][20]. Although the majority of systemic BMSCCs are trapped in the lungs after infusion and stayed in the body for no more than a few weeks, they produce antihyperalgesia that lasts for a few months, involving immune interactions and activation of the endogenous opioids [19,60].…”

“…To address this issue, we analyzed biting parameters during prolonged myofascial pain induced by ligation injury of the masseter muscle tendon (TL) in mice. Utilizing bone marrow stromal cells (BMSCs) that have been shown to attenuate persistent pain [17][18][19][20], we show that reduced bite force after TL was improved after infusion of BMSCs.…”