Alterations in Blood Methylome as Potential Epigenetic Biomarker in Sporadic Parkinson's Disease

OBJECTIVE

To characterize DNA methylation (DNAm) differences between sporadic Parkinson's disease (PD) and healthy control (HC) individuals enrolled in the Parkinson's Progression Markers Initiative (PPMI).

METHODS

Using whole blood, we characterized longitudinal differences in DNAm between sporadic PD patients (n = 196) and HCs (n = 86) enrolled in PPMI. RNA sequencing (RNAseq) was used to conduct gene expression analyses for genes mapped to differentially methylated cytosine-guanine sites (CpGs).

RESULTS

At the time of patient enrollment, 5,178 CpGs were differentially methylated (2,683 hypermethylated and 2,495 hypomethylated) in PD compared to HC. Of these, 579 CpGs underwent significant methylation changes over 3 years. Several differentially methylated CpGs were found near the cytochrome P450 family 2 subfamily E member 1 (CYP2E1) gene. Additionally, multiple hypermethylated CpGs were associated with the N-myc downregulated gene family member 4 (NDRG4) gene. RNA-Seq analyses showed 75 differentially expressed genes in PD patients compared to controls. An integrative analysis of both differentially methylated sites and differentially expressed genes revealed 20 genes that exhibited hypomethylation concomitant with overexpression. Additionally, 1 gene, cathepsin H (CTSH), displayed hypermethylation that was associated with its decreased expression.

INTERPRETATION

We provide initial evidence of alterations in DNAm in blood of PD patients that may serve as potential epigenetic biomarker of disease. To evaluate the significance of these changes throughout the progression of PD, additional profiling at longer intervals and during the prodromal stages of disease will be necessary. ANN NEUROL 2024;95:1162-1172.

Long-Term Use of Rimegepant 75 mg for the Acute Treatment of Migraine is Associated with a Reduction in the Utilization of Select Analgesics and Antiemetics

Purpose

To examine use of concomitant analgesics and antiemetics during treatment with rimegepant in adults with migraine.

Patients and Methods

This was a post hoc analysis of a long-term, open-label, safety study in adults with a history of 2-14 moderate or severe migraine attacks per month. Participants self-administered rimegepant 75 mg (1) up to once daily as needed (PRN) for 52 weeks or (2) every other day plus PRN (EOD+PRN) for 12 weeks. The PRN cohort was further divided based on baseline attack frequency, with PRN (2-8) and PRN (9-14) cohorts having a history of 2-8 or 9-14 attacks per month, respectively. Use of select analgesics and antiemetics was analyzed during a 30-day pre-treatment observation period (OP) and during rimegepant treatment.

Results

Overall, 1800 rimegepant-treated participants (PRN n = 1514, EOD+PRN n = 286) were included in the analysis. Select analgesics or antiemetics were used by 80.1% of participants during the OP. Among 1441 participants using analgesics or antiemetics during the OP, the proportion who did not use any analgesics or antiemetics following initiation of rimegepant treatment increased during weeks 1-4 (36.9%), 5-8 (52.6%), and 9-12 (56.5%). The mean number of days per month using analgesics or antiemetics was also significantly reduced over time in all cohorts beginning at weeks 1-4 (P < 0.001 vs OP). This pattern of reduced analgesic or antiemetic use was consistent for all rimegepant cohorts, but was most pronounced in the EOD+PRN cohort in which 74.8% of participants reported ≥50% reduction in analgesic/antiemetic days at weeks 9-12. Reduction in use was maintained over time, with 61.3% of participants not using any analgesics or antiemetics during weeks 49-52 of PRN treatment.

Conclusion

Long-term treatment with oral rimegepant was associated with reduced analgesic and antiemetic use. Clinicaltrials.gov: NCT03266588.