Role of α-CGRP in the regulation of neurotoxic responses induced by kainic acid in mice

Reconceptualizing autonomic function testing in migraine: a systematic review and meta-analysis

BACKGROUND

Autonomic nervous system (ANS) testing has aided in our ability to evaluate autonomic dysfunction in migraine patients. We reviewed the literature in multiple databases which investigate ANS function in migraine patients and healthy subjects.

METHODS

This systematic review and meta-analysis examined the respective deep breathing, Valsalva manoeuvre, orthostatic and isometric challenge results, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses of Observational Studies in Epidemiology (MOOSE) statements.

RESULTS

Seven articles met all inclusion criteria. Fixed-effects meta-analysis showed migraine patients (n = 424), collectively, had lower interictal autonomic test results compared with healthy controls (n = 268). In detail, this was true for the standardized mean difference (g) of deep breathing (g= -0.32; 95% confidence interval (CI) -0.48, -0.16), orthostatic challenge (g= -0.28; 95% CI -0.44, -0.13) and isometric challenge (g= -0.55; 95% CI -0.71, -0.39) and for the difference of means (MD) of the Valsalva ratio (MD = -0.17; 95% CI -0.23, -0.10).

CONCLUSIONS

Interictal ANS dysfunction can be identified in migraine patients when compared to healthy controls. These findings indicate the importance to evaluate ANS function in migraine patients - especially, as migraine-specific prophylactic therapies (such as anti-calcitonin gene-related peptide (CGRP) antibodies) may affect the function of the ANS.

Antiseizure Medications for the Prophylaxis of Migraine during the Anti- CGRP Drugs Era

Migraine and epilepsy are fundamentally distinct disorders that can frequently coexist in the same patient. These two conditions significantly differ in diagnosis and therapy but share some widely- used preventive treatments. Antiseizure medications (ASMs) are the mainstay of therapy for epilepsy, and about thirty different ASMs are available to date. ASMs are widely prescribed for other neurological and non-neurological conditions, including migraine. However, only topiramate and valproic acid/valproate currently have an indication for migraine prophylaxis supported by high-quality evidence. Although without specifically approved indications and with a low level of evidence or recommendation, several other ASMs are used for migraine prophylaxis. Understanding ASM antimigraine mechanisms, including their ability to affect the pro-migraine calcitonin gene-related peptide (CGRP) signaling pathway and other pathways, may be instrumental in identifying the specific targets of their antimigraine efficacy and may increase awareness of the neurobiological differences between epilepsy and migraine. Several new ASMs are under clinical testing or have been approved for epilepsy in recent years, providing novel potential drugs for migraine prevention to enrich the treatment armamentarium and drugs that inhibit the CGRP pathway.

[Protective effect of calcitonin gene-related peptide against oxidative damage in MC3T3-E1 osteoblasts]

OBJECTIVE

This study aimed to observe the protective effect of calcitonin gene-related peptide (CGRP), as well as its potential mechanism, against oxidative damage in MC3T3-E1 osteoblasts.

METHODS

1) MC3T3-E1 osteoblasts were treated with different hydrogen peroxide (H₂O₂) concentrations (10⁻¹, 10⁻², 10⁻³, 10⁻⁴, and 10⁻⁵ mol·L⁻¹) for 12, 24, 36, and 48 h to build an oxidative damage model, to determine cell proliferation activity in each group by using CCK-8 assay, and to determine the optimal modeling concentration. MC3T3-E1 osteoblasts were pretreated for 1 h with different CGRP concentrations (10⁻⁶, 10⁻⁷, 10⁻⁸, 10⁻⁹, and 10⁻¹⁰ mol·L⁻¹) followed by treatment with H₂O₂ (10⁻⁴ mol·L⁻¹). After 12, 24, 36, and 48 h, the CGRP expression and activity of osteoblasts were detected using the CCK-8 method to determine the optimal CGRP concentration that provides the best protective effect against oxidative damage. 2) Superoxide dismutase (SOD) activity, reactive oxygen species (ROS) content, and the levels of the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 of the groups treated with CGRP, H₂O₂, CGRP+H₂O₂ were determined.

RESULTS

1) Compared with the control group, treatment with 10⁻⁴ mol·L⁻¹ H₂O₂ significantly started to inhibite the proliferation of osteoblasts (P<0.01) in a dose- and time-dependent manner. Compared with 10⁻⁴ mol·L⁻¹ H₂O₂ group, pretreatment with 10⁻⁸ mol·L⁻¹ CGRP significantly increased the proliferation of osteoblasts (P<0.01). 2) Compared with H₂O₂ group, CGRP+H₂O₂ group significantly increased the SOD activity (P<0.01), ROS content significantly decreased (P<0.01), TNF-α, IL-1β, and IL-6 secretion significantly decreased (P<0.05).

CONCLUSIONS

H₂O₂ can cause oxidative damage to MC3T3-E1 osteoblasts, whereas CGRP exerts protective effect against oxidative damage in MC3T3-E1 osteoblasts.