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L type Ca²+ channel blockers prevent oxaliplatin-induced cold hyperalgesia and TRPM8 overexpression in rats.

Kawashiri T, Egashira N, Kurobe K, Tsutsumi K, Yamashita Y, Ushio S, Yano T, Oishi R - Mol Pain (2012)

Bottom Line: Furthermore, oxalate (1.3 mg/kg) significantly induced the increase in TRPM8 protein in the DRG.Treatment with oxaliplatin and oxalate (500 μM for each) also increased the TRPM8 mRNA levels and induced Ca²⁺ influx and nuclear factor of activated T-cell (NFAT) nuclear translocation in cultured DRG cells.These changes induced by oxalate were inhibited by nifedipine, diltiazem and mexiletine.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacy, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.

ABSTRACT

Background: Oxaliplatin is an important drug used in the treatment of colorectal cancer. However, it frequently causes severe acute and chronic peripheral neuropathies. We recently reported that repeated administration of oxaliplatin induced cold hyperalgesia in the early phase and mechanical allodynia in the late phase in rats, and that oxalate derived from oxaliplatin is involved in the cold hyperalgesia. In the present study, we examined the effects of Ca²⁺ channel blockers on oxaliplatin-induced cold hyperalgesia in rats.

Methods: Cold hyperalgesia was assessed by the acetone test. Oxaliplatin (4 mg/kg), sodium oxalate (1.3 mg/kg) or vehicle was injected i.p. on days 1 and 2. Ca²⁺ (diltiazem, nifedipine and ethosuximide) and Na⁺ (mexiletine) channel blockers were administered p.o. simultaneously with oxaliplatin or oxalate on days 1 and 2.

Results: Oxaliplatin (4 mg/kg) induced cold hyperalgesia and increased in the transient receptor potential melastatin 8 (TRPM8) mRNA levels in the dorsal root ganglia (DRG). Furthermore, oxalate (1.3 mg/kg) significantly induced the increase in TRPM8 protein in the DRG. Treatment with oxaliplatin and oxalate (500 μM for each) also increased the TRPM8 mRNA levels and induced Ca²⁺ influx and nuclear factor of activated T-cell (NFAT) nuclear translocation in cultured DRG cells. These changes induced by oxalate were inhibited by nifedipine, diltiazem and mexiletine. Interestingly, co-administration with nifedipine, diltiazem or mexiletine prevented the oxaliplatin-induced cold hyperalgesia and increase in the TRPM8 mRNA levels in the DRG.

Conclusions: These data suggest that the L type Ca²⁺ channels/NFAT/TRPM8 pathway is a downstream mediator for oxaliplatin-induced cold hyperalgesia, and that Ca²⁺ channel blockers have prophylactic potential for acute neuropathy.

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NFAT nuclear translocation in primary cultured DRG cells. Oxaliplatin (A, B: 500 μM for 1-6 h) or sodium oxalate (C, D: 500 μM for 1-6 h) was administered to cultured DRG cells. E, F: Mexiletine (Mex, 1 mM), nifedipine (Nif, 30 μM), diltiazem (Dil, 30 μM) or vivit (2 μM) was co-administered with sodium oxalate (500 μM) to cells for 6 h. NFATc4 immunostaining (green) and nuclear staining with DAPI (blue). NFATc4 and DAPI-positive nuclei were visualized by fluorescence microscopy (A, C, E). The nuclear translocation of NFATc4 was calculated by comparing the ratio of nuclear NFATc4 immunofluorescence/total NFATc4 immunofluorescence (B, D, F). Values are expressed as the mean ± SEM of 24-33 cells. ††p < 0.01 compared with control group, **p < 0.01 compared with oxalate group.
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Figure 3: NFAT nuclear translocation in primary cultured DRG cells. Oxaliplatin (A, B: 500 μM for 1-6 h) or sodium oxalate (C, D: 500 μM for 1-6 h) was administered to cultured DRG cells. E, F: Mexiletine (Mex, 1 mM), nifedipine (Nif, 30 μM), diltiazem (Dil, 30 μM) or vivit (2 μM) was co-administered with sodium oxalate (500 μM) to cells for 6 h. NFATc4 immunostaining (green) and nuclear staining with DAPI (blue). NFATc4 and DAPI-positive nuclei were visualized by fluorescence microscopy (A, C, E). The nuclear translocation of NFATc4 was calculated by comparing the ratio of nuclear NFATc4 immunofluorescence/total NFATc4 immunofluorescence (B, D, F). Values are expressed as the mean ± SEM of 24-33 cells. ††p < 0.01 compared with control group, **p < 0.01 compared with oxalate group.

Mentions: Treatment with oxaliplatin (500 μM) for 6 h induced NFAT nuclear translocation (Figure 3A, B, 6 h: p < 0.01). Similarly, 500 μM oxalate caused NFAT nuclear translocation (Figure 3C, D, 6 h: p < 0.01). Mexiletine (1 mM), nifedipine (30 μM) and diltiazem (30 μM) completely blocked the oxalate-induced NFAT nuclear translocation (500 μM) (Figure 3E, F, p < 0.01). Similarly, vivit (2 μM), a selective NFAT inhibitor, completely blocked the oxalate-induced NFAT nuclear translocation (Figure 3E, F, p < 0.01).


L type Ca²+ channel blockers prevent oxaliplatin-induced cold hyperalgesia and TRPM8 overexpression in rats.

Kawashiri T, Egashira N, Kurobe K, Tsutsumi K, Yamashita Y, Ushio S, Yano T, Oishi R - Mol Pain (2012)

NFAT nuclear translocation in primary cultured DRG cells. Oxaliplatin (A, B: 500 μM for 1-6 h) or sodium oxalate (C, D: 500 μM for 1-6 h) was administered to cultured DRG cells. E, F: Mexiletine (Mex, 1 mM), nifedipine (Nif, 30 μM), diltiazem (Dil, 30 μM) or vivit (2 μM) was co-administered with sodium oxalate (500 μM) to cells for 6 h. NFATc4 immunostaining (green) and nuclear staining with DAPI (blue). NFATc4 and DAPI-positive nuclei were visualized by fluorescence microscopy (A, C, E). The nuclear translocation of NFATc4 was calculated by comparing the ratio of nuclear NFATc4 immunofluorescence/total NFATc4 immunofluorescence (B, D, F). Values are expressed as the mean ± SEM of 24-33 cells. ††p < 0.01 compared with control group, **p < 0.01 compared with oxalate group.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 3: NFAT nuclear translocation in primary cultured DRG cells. Oxaliplatin (A, B: 500 μM for 1-6 h) or sodium oxalate (C, D: 500 μM for 1-6 h) was administered to cultured DRG cells. E, F: Mexiletine (Mex, 1 mM), nifedipine (Nif, 30 μM), diltiazem (Dil, 30 μM) or vivit (2 μM) was co-administered with sodium oxalate (500 μM) to cells for 6 h. NFATc4 immunostaining (green) and nuclear staining with DAPI (blue). NFATc4 and DAPI-positive nuclei were visualized by fluorescence microscopy (A, C, E). The nuclear translocation of NFATc4 was calculated by comparing the ratio of nuclear NFATc4 immunofluorescence/total NFATc4 immunofluorescence (B, D, F). Values are expressed as the mean ± SEM of 24-33 cells. ††p < 0.01 compared with control group, **p < 0.01 compared with oxalate group.
Mentions: Treatment with oxaliplatin (500 μM) for 6 h induced NFAT nuclear translocation (Figure 3A, B, 6 h: p < 0.01). Similarly, 500 μM oxalate caused NFAT nuclear translocation (Figure 3C, D, 6 h: p < 0.01). Mexiletine (1 mM), nifedipine (30 μM) and diltiazem (30 μM) completely blocked the oxalate-induced NFAT nuclear translocation (500 μM) (Figure 3E, F, p < 0.01). Similarly, vivit (2 μM), a selective NFAT inhibitor, completely blocked the oxalate-induced NFAT nuclear translocation (Figure 3E, F, p < 0.01).

Bottom Line: Furthermore, oxalate (1.3 mg/kg) significantly induced the increase in TRPM8 protein in the DRG.Treatment with oxaliplatin and oxalate (500 μM for each) also increased the TRPM8 mRNA levels and induced Ca²⁺ influx and nuclear factor of activated T-cell (NFAT) nuclear translocation in cultured DRG cells.These changes induced by oxalate were inhibited by nifedipine, diltiazem and mexiletine.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pharmacy, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.

ABSTRACT

Background: Oxaliplatin is an important drug used in the treatment of colorectal cancer. However, it frequently causes severe acute and chronic peripheral neuropathies. We recently reported that repeated administration of oxaliplatin induced cold hyperalgesia in the early phase and mechanical allodynia in the late phase in rats, and that oxalate derived from oxaliplatin is involved in the cold hyperalgesia. In the present study, we examined the effects of Ca²⁺ channel blockers on oxaliplatin-induced cold hyperalgesia in rats.

Methods: Cold hyperalgesia was assessed by the acetone test. Oxaliplatin (4 mg/kg), sodium oxalate (1.3 mg/kg) or vehicle was injected i.p. on days 1 and 2. Ca²⁺ (diltiazem, nifedipine and ethosuximide) and Na⁺ (mexiletine) channel blockers were administered p.o. simultaneously with oxaliplatin or oxalate on days 1 and 2.

Results: Oxaliplatin (4 mg/kg) induced cold hyperalgesia and increased in the transient receptor potential melastatin 8 (TRPM8) mRNA levels in the dorsal root ganglia (DRG). Furthermore, oxalate (1.3 mg/kg) significantly induced the increase in TRPM8 protein in the DRG. Treatment with oxaliplatin and oxalate (500 μM for each) also increased the TRPM8 mRNA levels and induced Ca²⁺ influx and nuclear factor of activated T-cell (NFAT) nuclear translocation in cultured DRG cells. These changes induced by oxalate were inhibited by nifedipine, diltiazem and mexiletine. Interestingly, co-administration with nifedipine, diltiazem or mexiletine prevented the oxaliplatin-induced cold hyperalgesia and increase in the TRPM8 mRNA levels in the DRG.

Conclusions: These data suggest that the L type Ca²⁺ channels/NFAT/TRPM8 pathway is a downstream mediator for oxaliplatin-induced cold hyperalgesia, and that Ca²⁺ channel blockers have prophylactic potential for acute neuropathy.

Show MeSH
Related in: MedlinePlus