Glial Fibrillary Acidic Protein In Spinal Cord Research Articles

Acupuncture for Cancer-Induced Bone Pain in Animal Models: A Systemic Review and Meta-Analysis.

Background Cancer-induced bone pain (CIBP) is a highly prevalent symptom, which afflicts vast majority of patients who suffer from cancer. The current treatment options failed to achieve satisfactory effect and the side effects were prominent. Recent randomized controlled trials (RCTs) of animal demonstrate the benefit of acupuncture for CIBP. We sought to determine if the pooled data from available RCTs supports the use of acupuncture for CIBP. Methods A literature search for randomized controlled trials was conducted in six electronic databases from inception to May 31, 2019. Meta-analysis was performed with Review Manager 5.3 software; the publication bias was assessed by Stata 12.0 software. We used random effects model for pooling data because heterogeneity is absolute among studies to some extent. Results Twenty-four trials were included in the review, of which 12 trials provided detailed data for meta-analyses. Preliminary evidence indicates that compared to wait list/sham group, acupuncture was effective on increasing paw withdrawal threshold (PWT) and paw withdrawal latency (PWL). Compared to medicine, acupuncture was less effective on PWT, but as effective as medicine on PWL. Acupuncture can reinforce medicine's effect on PWT and PWL. Compared to the control group, acupuncture was superior to increase body weight (BW), decrease spinal cord glial fibrillary acidic protein (GFAP), and interleukin-1β (IL-1β). Furthermore, some studies showed acupuncture delay or partially reverse morphine tolerance. Three studies found acupuncture has no effect on PWT, but 2 of them found acupuncture could enhance small dose of Celebrex's effect on CIBP. Conclusions Acupuncture was superior to wait list/sham acupuncture on increasing PWT and has no less effect on increasing PWL compared to medicine; acupuncture improved the efficacy of drugs, increased the CIBP animals' body weight, and decreased their spinal cord GFAP and IL-1β. High-quality studies are necessary to confirm the results.

Thalidomide alleviates bone cancer pain by down-regulating expressions of NF-κB and GFAP in spinal astrocytes in a mouse model

Aim: Thalidomide is one of the first line therapies in cancer pain management. Previous study has shown that thalidomide decreases the expression of tumor necrosis factor alpha in the mouse spinal cord. However, the exact cellular and molecular mechanism underlying the effect of thalidomide remains unclear. Here, we investigated the effect of thalidomide on the expression level of NF-κB as well as glial fibrillary acidic protein (GFAP) in the spinal cord astrocyte in a mice model.Materials and methods: MC57G fibrosarcoma cells were intramedullary injected into the right femurs of C57/BL mice to induce behaviors related to bone cancer pain. Postoperative thalidomide was administered intraperitoneally to the mice at dose of 100 mg/kg/day for 7 days. The effect of thalidomide on pain hypersensitivity was checked by behavioral testing. The expression levels of NF-κB and GFAP in spinal cord were evaluated by using Western blotting and Immunohistochemistry.Results: Compared with the controls, the tumor-bearing mice showed substantial pain-related behaviors. Furthermore, the expression levels of both NF-κB and GFAP increased significantly in the spinal cord astrocytes of the tumor-bearing mice. Treating the tumor-bearing mice with thalidomide results in a dramatic reduction in pain behaviors and a significant decrease of NF-κB and GFAP expressions.Conclusions: Thalidomide alleviates the pain behaviors probably by down-regulating the expression of NF-κB and GFAP.

Intrathecal injection of AG-490 reduces bone-cancer-induced spinal cord astrocyte reaction and thermal hyperalgesia in a mouse model

To investigate the role of spinal interleukin-6-Janus kinase 2 (IL-6-JAK2) signaling transduction pathway in regulating astrocytes activation during the maintenance of bone cancer pain (BCP). Methods: NCTC 2472 fibrosarcoma cells were injected into the femur marrow cavity in C3H/HeNCrlVr male mice to establish BCP model and they were replaced by the equal volume of α-MEM in the sham model. The paw withdrawal latency (PWL) was measured after inoculation of tumor cells. The lumbar enlargement of spinal cord (L3-L5) was isolated, and Real-time RT-PCR and Western blot were used to detect the expression of spinal glial fibrillary acidic protein (GFAP) and JAK2 mRNA and protein, respectively. The expression level of spinal GFAP mRNA indirectly reflect astrocytes activation level. Pain behaviors and spinal cord GFAP mRNA and protein expression were observed at the given time points after intrathecal administration of JAK2 antagonist AG-490. Results: The PWL at 10, 14, 21 d after operation in BCP model group were significantly shorter than that in the sham group (P<0.05); the spinal GFAP and JAK2 mRNA and protein levels were higher in the BCP model group in comparison to mice in the sham group (P<0.05); intrathecal injection of JAK2 agonist AG-490 (30 or 90 nmol) significantly alleviated PWL, and downregulated the expression of spinal GFAP mRNA and protein (P<0.05). Conclusion: The IL-6-JAK2 signaling pathway plays an important role in maintaining the BCP by regulating the expression of GFAP in the spinal cord. Intrathecal injection of AG-490 can reduce the BCP, and inhibit the activation of IL-6-JAK2 signaling pathway, which may be one of the mechanisms for spinal astrocyte activation.

Astrocyte heterogeneity across the brain and spinal cord occurs developmentally, in adulthood and in response to demyelination.

Astrocytes have emerged as essential regulators of function and response to injury in the brain and spinal cord, yet very little is known about regional differences that exist. Here we compare the expression of key astroglial markers (glial fibrillary acidic protein (GFAP) and Aldehyde Dehydrogenase-1 Family Member L1 (ALDH1L1)) across these disparate poles of the neuraxis, tracking their expression developmentally and in the context of demyelination. In addition, we document changes in the astrocyte regulatory cytokine interleukin 6 (IL-6), and its signaling partner signal transducer and activator of transcription 3 (STAT3), in vivo and in vitro. Results demonstrate that GFAP expression is higher in the developing and adult spinal cord relative to brain. Comparisons between GFAP and ALDH1L1 expression suggest elevations in spinal cord GFAP during the early postnatal period reflect an accelerated appearance of astrocytes, while elevations in adulthood reflect higher expression by individual astrocytes. Notably, increases in spinal cord compared to whole brain GFAP were paralleled by higher levels of IL-6 and STAT3. Equivalent elevations in GFAP, GFAP/ALDH1L1 ratios, and in IL-6, were observed in primary astrocyte cultures derived from spinal cord compared to cortex. Also, higher levels of GFAP were observed in the spinal cord compared to the brain after focal demyelinating injury. Altogether, these studies point to key differences in astrocyte abundance and the expression of GFAP and IL-6 across the brain and spinal cord that are positioned to influence regional specialization developmentally and responses occurring in the context of injury and disease.

Therapeutic effect of melittin on a rat model of chronic prostatitis induced by Complete Freund’s Adjuvant

ObjectivesThe present study was aimed to establish a model of chronic prostatitis in rat with the use of intraprostatic injection of Complete Freund’s Adjuvant, and to examine the anti-inflammatory and analgesic effects of melittin on the newly-developed chronic prostatic pain model. MethodsAdult male Sprague-Dawley rats were injected with Complete Freund’s Adjuvant (CFA) into the prostate. Twelve days after model rats of the treatment group were injected melittin into the prostate, while those of the control group received sterile saline injection. The nociceptive effects of CFA were evaluated by using a behavior approach (i.e. mechanical pain threshold measurement) on the day of CFA injection and 6, 12, and 18days after CFA injection. After the in-live study was done, the prostate was collected for histological examination of inflammatory cell infiltration. Levels of cyclooxygenase (COX)-2 in prostate and glial fibrillary acidic protein (GFAP) in spinal cord were determined using immunohistochemistry. Rats of the sham control group received intraprostatic injection of sterile saline and were studied using the same methods ResultsIntraprostatic CFA injection induced local allodynia that lasted over at least 2 weeks. The pain behavior of rat was associated with increases in inflammatory cell infiltration into the prostate. Levels of COX-2 in prostate and GFAP in spinal cord were also elevated. Treatment with melittin significantly raised pain threshold, decreased inflammatory infiltrates, and suppressed COX-2 and GFAP expression. ConclusionIntraprostatic injection of CFA induced neurogenic prostatitis and prostatic pain. The established model will be useful to the study of CP/CPPS pathogenesis. Melittin demonstrated profound anti-inflammatory and analgesic effects on the chronic prostatic pain model, suggesting melittin may hold promise as a novel therapeutic for treatment of CP/CPPS.

Role of Melatonin in the Prevention of Morphine-Induced Hyperalgesia and Spinal Glial Activation in Rats: Protein Kinase C Pathway Involved

ABSTRACTPurposes: Morphine can induce tolerance and hyperalgesia after long-term administration. Glial activation is believed to cause and maintain a state of morphine-induced pain hypersensitivity. The present study examines the effect of melatonin on tolerance, hyperalgesia, and reactive gliosis induced by morphine in rats. Methods: The study examines the effect of melatonin on morphine-induced hyperalgesia using tail-flick test. Immunohistochemistry and Western blot was performed to investigate the expression of glial fibrillary acidic protein (GFAP) indicative of spinal glial activity. This study also measures protein kinase C (PKC) activity and cyclic adenosine monophosphate (cAMP) levels in spinal cords to investigate the mechanisms which melatonin involved. Results: When coadministered intragastrically (i.g.) with morphine, melatonin in doses of 50 or 100 mg/kg significantly prevented hyperalgesia after termination of morphine. Immunohistochemistry and Western blot with GFAP revealed that melatonin significantly decreased morphine-induced over-expression of GFAP in spinal cord (p < .05). By measuring PKC activity and cAMP levels, the upregulated PKC activity and cAMP levels induced by morphine were significantly inhibited by melatonin. Conclusions: Melatonin can prevent morphine-withdrawal-induced hyperalgesia and glial reactivity. This effect of melatonin after morphine administration may mediated by inhibiting PKC activity and cAMP upregulation.

Glial fibrillary acidic protein increases in the spinal cord of Lewis rats with acute experimental autoimmune encephalomyelitis.

Glial fibrillary acidic protein (GFAP) in the spinal cords of Lewis rats with acute experimental autoimmune encephalomyelitis (EAE) was quantitated by densitometry of both stained gels and immunoblots of electrophoretically separated cytoskeletal proteins. The experimental period ranged from 7 to 65 days postinoculation (dpi). Greater than 92% of the total spinal cord GFAP was recovered in the Triton-insoluble cytoskeletal pellet; less than 2% was truly soluble. GFAP increased gradually and significantly with time, reaching a level one-and-a-half to two times greater than that of controls by 35 dpi and remaining elevated at 65 dpi. In EAE animals, GFAP was 33% of the total Triton-insoluble protein (excluding histones and other small basic proteins) at 7 dpi, rising to 48% at 65 dpi. Increases in vimentin were also noted, following a time course similar to that of GFAP. An increase in immunocytochemical staining of GFAP was noticeable at 10 dpi and became marked at 14 dpi, a time before GFAP levels had increased significantly. Thus, enhanced staining at the peak of the disease cannot be explained simply by an increase in antigen protein. Other possible explanations, such as an increase in soluble GFAP content, proteolytic degradation, or modifications in the immunochemical properties of GFAP in EAE animals, were ruled out. Both the biochemical and immunocytochemical increases in GFAP persisted through 65 dpi, even though the animals recovered from clinical signs at approximately 18 dpi.

Turnover of glial filaments in mouse spinal cord.

Twenty-day-old mice received a single tail vein injection of [guanido-14C]arginine. The cytoskeleton was extracted from the spinal cords at varying lengths of time thereafter. Glial fibrillary acidic protein (GFAP) formed a distinct, broad band that was widely separated from other protein bands in one-dimensional polyacrylamide gels. The purity of the GFAP band was verified by Western blot analysis of one- and two-dimensional electrophoretic patterns. In addition, enzyme-linked immunosorbent assay and quantitative Western blot analysis indicated that 95% of the total spinal cord GFAP was extracted in the cytoskeletal preparation. The specific activity of GFAP was obtained by eluting the protein from the cytoskeletal GFAP band in preparative one-dimensional gels. Specific activity reached a peak 2 h after injection with [14C]arginine. Forty percent of the incorporated radioactivity was still present in cytoskeletal GFAP at 9 weeks, indicating that a significant proportion of glial filaments turns over relatively slowly in vivo.