Journal: The Journal of Neuroscience

Article Title: CD44 Signaling Mediates High Molecular Weight Hyaluronan-Induced Antihyperalgesia

doi: 10.1523/JNEUROSCI.2695-17.2017

Figure Lengend Snippet: Antihyperalgesic effect of HMWH. A, LMWH (1 μg) was injected intradermally on the dorsum of the hindpaw. Ten minutes later, HMWH (1 μg, black circles) or vehicle (open circles) was injected at the same site and the mechanical nociceptive threshold evaluated over time. Significant reversal of LMWH-induced hyperalgesia was observed in the group treated with HMWH (F(1.16) = 83.33, ****p < 0.0001, when both groups are compared, two-way repeated-measures ANOVA, followed by Bonferroni post hoc test). B, Four pronociceptive mediators, PGE2 (100 ng), epinephrine (epi, 100 ng), TNFα (100 ng), or IL-6 (10 ng), were injected intradermally on the dorsum of the hindpaw. Ten minutes after PGE2 and epinephrine, or 30 min after TNFα and IL-6, HMWH (1 μg, black bars) or vehicle (white bars) was injected at the same site. Measurement of the mechanical nociceptive threshold after an additional 30 min showed a significant attenuation of the hyperalgesia induced by all four pronociceptive mediators, in the groups treated with HMWH (PGE2 groups: t(10) = 5.676, ***p = 0.0001; epi groups: t(10) = 4.150, **p = 0.0010; TNFα groups: t(10) = 6.365, ****p < 0.0001; IL-6 groups: t(10) = 5.461, ***p = 0.0001, when the vehicle and HMWH groups are compared, unpaired Student's t test). C, Rats received four intraperitoneal injections of the neurotoxic chemotherapeutic drug paclitaxel (1 mg/kg), once every other day. Evaluation of mechanical nociceptive threshold 24 h after the last injection of paclitaxel showed robust mechanical hyperalgesia. Then HMWH (1 μg, black bar) or vehicle (white bar) was injected intradermally at the site of nociceptive testing on the dorsum of the hindpaw. Mechanical nociceptive threshold was again evaluated 30 min later. Whereas hyperalgesia was still observed in the vehicle-treated group, in the group that received HMWH, it was markedly attenuated (t(10) = 4.677, ###p = 0.0004, when control and HMWH groups are compared, unpaired Student's t test). A, Control group, n = 12 paws; HMWH group, n = 6. B, C, All groups, n = 6 paws.

Article Snippet: The following drugs were used in this study: hyaluronic acid sodium salt from Streptococcus pyrogenes (HMWH), from Calbiochem; epinephrine, prostaglandin E 2 (PGE 2 ), hyaluronic acid sodium salt from Streptococcus equi (LMWH), and the cancer chemotherapeutic agent paclitaxel, from Sigma-Aldrich; a peptide CD44 receptor agonist A6 ( Piotrowicz et al., 2011 ; Finlayson, 2015 ) from GenScript; rat recombinant interleukin-6 (IL-6) and rat recombinant TNFα, from R&D Systems; the selective activator of PKCε, psi ε Receptor for Activated C Kinase (ψεRACK), from Biomatik; and the potent membrane-permeable cAMP analog 8-bromo cAMP sodium salt (Tocris Bioscience).

Techniques: Injection

Journal: The Journal of Neuroscience

Article Title: CD44 Signaling Mediates High Molecular Weight Hyaluronan-Induced Antihyperalgesia

doi: 10.1523/JNEUROSCI.2695-17.2017

Figure Lengend Snippet: Antihyperalgesic effect of HMWH is CD44-dependent. A, Rats were treated daily with a spinal intrathecal injection of ODN sense or antisense for CD44 mRNA (120 μg) for 3 consecutive days. On the fourth day, TNFα (100 ng, left) or IL-6 (10 ng, right) was injected intradermally on the dorsum of the hindpaw. Thirty minutes later, vehicle (white bars) or HMWH (1 μg, black bars) was injected at the same site. Evaluation of the mechanical nociceptive threshold 30 min later showed a significant reversal of the hyperalgesia induced by TNFα and IL-6 in the groups that had been treated with antisense, compared with those treated with sense (TNFα, sense groups: t(10) = 7.306, ****p < 0.0001; antisense groups: t(10) = 1.007, p = 0.1688, nonsignificant; IL-6, sense groups: t(10) = 9.077, ****p < 0.0001; antisense groups: t(10) = 0.8891, p = 0.1974, nonsignificant, when the vehicle and HMWH groups are compared, unpaired Student's t test). B, Rats received four intraperitoneal injections of the chemotherapeutic drug paclitaxel (1 mg/kg, every other day). Intrathecal injections of ODN sense or antisense were performed, once a day, from days 5–7 of paclitaxel treatment. At 24 h after the last injections of paclitaxel and ODNs, vehicle (white bars) or HMWH (1 μg, black bars) was injected intradermally on the dorsum of the hindpaw. Mechanical nociceptive threshold was evaluated before treatment with paclitaxel and 30 min after the injection of vehicle or HMWH. Significant attenuation of paclitaxel-induced hyperalgesia was observed only in the ODN sense-treated group (t(10) = 4.781, ***p = 0.0004, compared with the antisense-treated group, unpaired Student's t test). Together, these results indicate that HMWH acts at CD44 to produce antihyperalgesia. n = 6 paws, all groups.

Article Snippet: The following drugs were used in this study: hyaluronic acid sodium salt from Streptococcus pyrogenes (HMWH), from Calbiochem; epinephrine, prostaglandin E 2 (PGE 2 ), hyaluronic acid sodium salt from Streptococcus equi (LMWH), and the cancer chemotherapeutic agent paclitaxel, from Sigma-Aldrich; a peptide CD44 receptor agonist A6 ( Piotrowicz et al., 2011 ; Finlayson, 2015 ) from GenScript; rat recombinant interleukin-6 (IL-6) and rat recombinant TNFα, from R&D Systems; the selective activator of PKCε, psi ε Receptor for Activated C Kinase (ψεRACK), from Biomatik; and the potent membrane-permeable cAMP analog 8-bromo cAMP sodium salt (Tocris Bioscience).

Techniques: Injection