Enhanced NLRP3, caspase-1, and IL- 1ß levels in degenerate human intervertebral disc and their association with the grades of disc degeneration.

The NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome plays an important role in a variety of diseases. However, the role of NLRP3 in the human intervertebral disc (IVD) degeneration remains unknown. In the present study, we assessed the expression levels of the NLRP3 inflammasome and its downstream targets caspase-1 and IL-1ß in 45 degenerate and seven nondegenerate IVD samples. The correlation between the degeneration scores and expression levels of NLRP3, caspase-1, and IL-1ß were also analyzed. The mRNA expression levels of the three molecules (NLRP3, caspase-1, and IL-1ß) were higher in the degenerate IVDs group than the controls (nondegenerate IVDs group). Immunohistochemistry showed that the expression levels of all three molecules were markedly increased in the nucleus pulposus of degenerate IVDs compared with nondegenerate IVDs. There was a positive correlation between the degeneration scores and the expression levels of the NLRP3 inflammasome as well as its downstream targets caspase-1 and IL-1ß. The findings suggest that excessive activation of the NLRP3 inflammasome results in overproduction of downstream IL-1ß, which participates in the pathogenesis of human IVD degeneration. Therefore, the NLRP3 inflammasome might serve as a potential therapeutic target for the prevention and treatment of IVD degeneration.

Loss of ICA69 potentiates long-lasting hyperalgesia after subcutaneous formalin injection into the mouse hindpaw.

Islet-cell autoantigen 69 kDa (ICA69) plays an important role in many diseases and physiological activities by forming heteromeric complexes with protein interacts with C-kinase 1 (PICK1). PICK1 is critical for inflammatory pain hypersensitivity by regulating trafficking of AMPA receptor subunit GluA2 in spinal neurons. However, the role of ICA69 in inflammatory pain has not yet been investigated. Here we reported that expression of PICK1 in spinal cord was reduced largely in ICA69 knockout mice. The pain hypersensitivity was enhanced in the second phase 7 days after formalin administration. Meanwhile, increased Ser880 phosphorylation in GluA2 and decreased surface GluA2 were concordant with the pain. Furthermore, the number of activated microglia in spinal dorsal horn increased in line with pain hypersensitivity. Together, ICA69 deficiency promoted the internalization of GluA2 and FML-induced long-lasting pain hypersensitivity. In addition, microglia activation might be an important factor in the development of the pain hypersensitivity.

[Effect of ginsenoside Rb1 on cerebral infarction volume and IL-1 beta in the brain tissue and sera of focal cerebral ischemia/reperfusion injury model rats].

OBJECTIVE: To investigate the effect of ginsenoside Rb1 on cerebral infarction volume as well as IL-1 beta in the brain tissue and sera of focal cerebral ischemia/reperfusion (I/R) injury model rats. METHODS: The I/R rat model was established by using thread according to Zea-Longa. SD rats were randomly divided into five groups, i.e., the sham-operation group, the model group, the low dose ginsenoside Rb1 (20 mg/kg) group, the medium dose ginsenoside Rb1 group (40 mg/kg), and the high dose ginsenoside Rb1 group (80 mg/kg), 12 in each group. Rats in the sham-operation group only received middle cerebral artery occlusion (MCAO) but without thread insertion. The MCAO model was prepared in the rest 4 groups, followed by MCAO2 h later. Ginsenoside Rb1 at each dose was peritoneally administrated to rats in corresponding groups immediately after cerebral ischemia. Equal volume of normal saline was administered to rats in the sham-operation group. Rats' cerebral infarction volume, integrals of neurologic defect degree, expression of IL-1 beta content in the brain tissue and sera were observed 24 h after 2-h cerebral I/R. RESULTS: In the model group, integrals of neurologic defect degree were improved (P < 0.01), IL-1 beta positive cells in the brain tissue increased and serum IL-1 beta content elevated (P < 0.05), when compared with the sham-operation group. In comparison of the model group, integrals of neurologic defect degree were lowered in the medium dose and high dose ginsenoside Rb1 groups (P < 0.05, P < 0.01). The cerebral infarction volume was all shrunken in each ginsenoside Rb1 group, IL-1 beta positive cells in the brain tissue decreased, and IL-1 beta content in serum reduced (P < 0.01, P < 0.05). Compared with the low dose ginsenoside Rb1 group, integrals of neurologic defect degree decreased, the cerebral infarction volume shrunken, and IL-1 beta content in serum reduced in the high dose ginsenoside Rb1 group (P < 0.01, P < 0.05). CONCLUSION: Ginsenoside Rb1 (20, 40, 80 mg/kg) might effectively release local cerebral ischemia by down-regulating the IL-1 beta expression.