VTA-NAc glutaminergic projection involves in the regulation of pain and pain-related anxiety.

Background: Besides the established role of dopamine neurons and projections in nociceptive stimuli, the involvement of ventral tegmental area (VTA) glutamatergic projections to nucleus accumbens (NAc) in pain remains unknown. In the present study, we aimed to examine the role of VTA glutamatergic projections to NAc in painful stimuli and its related behavioral changes. Methods: Unilateral chronic constrictive injury (CCI) of sciatic nerve or intraplantar hind paw injections (i.pl.) of complete Freund's adjuvant (CFA) were used to develop pathological pain models in wild-type and VGluT2-Cre mice. The involvement of VTA glutamatergic neurons with projections to NAc in CCI-induced pain model was noted by c-Fos labeling and firing rate recordings. Pain response and pain-related behavior changes to the artificial manipulation of the VTA glutamatergic projections to NAc were observed by Hargreaves tests, von Frey tests, open field tests, elevated maze tests, and sucrose preference tests. Results: Glutamatergic neurons in VTA had efferent inputs to shell area of the NAc. The CCI pain model significantly increased neuronal activity and firing rate in VTA glutamate neurons with projections to NAc. The photoinhibition of these glutamatergic projections relieved CCI-induced neuropathic pain and CFA-induced acute and chronic inflammatory pain. Moreover, pathological neuropathic pain-induced anxiety and less sucrose preference were also relieved by inhibiting the VTA glutamatergic projections to NAc. Conclusion: Together, glutamatergic inputs from VTA to NAc contribute to chronic neuropathic and inflammatory pain and pain-related anxiety and depressive behaviors, providing a mechanism for developing novel therapeutic methods.

[Clinical observation on horizontal penetration needling combined with rizatriptan monobenzoate tablets for migraine without aura in acute stage].

OBJECTIVE: To observe the therapeutic effect of horizontal penetration needling combined with rizatriptan monobenzoate tablets, simple horizontal penetration needling and simple rizatriptan monobenzoate tablets for migraine without aura in acute stage. METHODS: A total of 99 patients with migraine without aura in acute stage were randomized into an acupuncture plus medication group, an acupuncture group and a western medication group, 33 cases in each one. In the acupuncture group, horizontal penetration needling was applied once at Hanyan (GB 4) to Xuanli(GB 6), Shenting (GV 24) to Yintang (GV 29), Baihui (GV 20) to Qianding (GV 21), etc. for 2 h. In the western medication group, oral rizatriptan monobenzoate tablets for 10 mg were given once. In the acupuncture plus medication group, treatment of acupuncture combined with rizatriptan monobenzoate tablets were given, the application was the same as the acupuncture group and the western medication group. Before treatment and 0.5, 2, 24 h after treatment, the visual analogue scale (VAS) score was observed, the remission rate and the disappearance rate of migraine of 2, 24 h after treatment were compared in the 3 groups. RESULTS: Compared before treatment, the VAS scores of each time point after treatment were decreased in the 3 groups (P<0.05), and the changes in the acupuncture plus medication group were greater than those in the acupuncture group and the western medication group (P<0.05). The remission rates of 24 h after treatment and the disappearance rates of migraine of 2, 24 h after treatment in the acupuncture plus medication group were higher than those in the acupuncture group and the western medication group (P<0.05). CONCLUSION: Horizontal penetration needling combined with rizatriptan monobenzoate tablets have significant therapeutic effect on rapid analgesia and continuous analgesia for migraine without aura in acute stage, its effect is superior to simple horizontal penetration needling and simple rizatriptan monobenzoate tablets.

Agglutinin isolated from Arisema heterophyllum Blume induces apoptosis and autophagy in A549 cells through inhibiting PI3K/Akt pathway and inducing ER stress.

Arisaema heterophyllum Blume is one of the three medicinal plants known as traditional Chinese medicine Rhizoma Arisaematis (RA). RA has been popularly used to treat patients with convulsions, inflammation, and cancer for a long time. However, the underlying mechanisms for RA effects are still unclear. The present study was designed to determine the cytotoxicity of agglutinin isolated from Arisema heterophyllum Blume (AHA) and explore the possible mechanisms in human non-small-cell lung cancer A549 cells. AHA with purity up to 95% was isolated and purified from Arisaema heterophyllum Blume using hydrophobic interaction chromatography. AHA dose-dependently inhibited the proliferation of A549 cells and induced G1 phase cell cycle arrest. AHA induced apoptosis by up-regulating pro-apoptotic Bax, decreasing anti-apoptotic Bcl-2, and activating caspase-9 and caspase-3. In A549 cells treated with AHA, the PI3K/Akt pathway was inhibited. Furthermore, AHA induced increase in the levels of ER stress markers such as phosphorylated eukaryotic initiation factor 2α (p-eIF2α), C/EBP-homologous protein (CHOP), inositol-requiring enzyme 1α (IRE1α), and phosphorylated c-Jun NH2-terminal kinase (p-JNK). AHA also induced autophagy in A549 cells. Staining of acidic vesicular organelles (AVOs) and increase in the levels of LC3II and ATG7 were observed in AHA-treated cells. These findings suggested that AHA might be one of the active components with anti-cancer effects in Arisaema heterophyllum Blume. In conclusion, cytotoxicity of AHA on cancer cells might be related to its effects on apoptosis and autophagy through inhibition of PI3K/Akt pathway and induction of ER stress.

Colocalization of insulin-like growth factor-1 receptor and T type Cav3.2 channel in dorsal root ganglia in chronic inflammatory pain mouse model.

Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays important roles in the nervous system. Increasing evidence supports that IGF-1 contributes to pain hypersensitivity through its insulin-like growth factor-1 receptor (IGF-1R) by activating IGF-1R/Akt or MAPK signaling pathways, whereas T-type Cav3.2 channel can facilitate and amplify pain signals originating from the sensory periphery. A recent study showed that activated IGF-1R can increase T-type Cav3.2 channel currents and further activate the G protein-dependent PKCα pathway to contribute to inflammatory pain sensitivity. However, the colocalization of IGF-1R and Cav3.2 in mouse dorsal root ganglion (DRG) under chronic inflammatory pain conditions remains elusive. In this study, we investigated changes in the expression of IGF-1R and the Cav3.2 channel, and their colocalization in mouse DRGs in chronic inflammatory pain condition (induced by complete Freund's adjuvant intraplanter injection) using real-time RT-PCR and immunohistochemistry approaches to confirm that Cav3.2 channel can mediate pain facilitation following IGF-1/IGF-1R signaling. We found that IGF-1R was expressed extensively in DRG neurons including small-, medium-, and large-sized neurons, whereas Cav3.2 channel was expressed exclusively in small-sized DRG neurons of naive mice. Expression of Cav3.2, but not IGF-1R, and colocalization of Cav3.2 and IGF-1R were increased in lumbar (L)4-L6 primary sensory neurons in DRGs of mice in chronic inflammatory pain. Moreover, the increased colocalization of IGF-1R and Cav3.2 is exclusively localized in small- and medium-sized primary sensory neurons. Our findings provided morphological evidence that T-type Cav3.2 channel, at least partially, mediates the pain facilitation of IGF-1/IGF-1R signaling in chronic inflammatory pain condition.