Circadian regulation of chemotherapy-induced peripheral neuropathic pain and the underlying transcriptomic landscape

Abstract

Growing evidence demonstrates circadian rhythms of pain hypersensitivity in various chronic disorders. In chemotherapy-induced peripheral neuropathy (CIPN), agents such as paclitaxel are known to elicit chronic neuropathic pain in cancer patients and seriously compromise their quality of life. Here, we report that the mechanical threshold for allodynia in paclitaxel-treated rats exhibited a robust circadian oscillation, reaching the nadir during the daytime (inactive phase). Using Per2::LucSV circadian reporter mice expressing a PER2::LUC fusion protein, we isolated dorsal root ganglia (DRG), the primary sensory cell body for peripheral nerve injury generated hypersensitivity, and monitored ex vivo reporter bioluminescence. We observed strong circadian reporter rhythms in DRG neurons which are highly entrainable by external cues. Paclitaxel treatment significantly lengthened DRG circadian periods, with little effects on the amplitude of oscillation. We further observed the core protein BMAL1 and PER2 in DRG neurons and satellite cells. Using DRG and dorsal horn (DH; another key structure for CIPN pain response) tissues from vehicle and paclitaxel treated rats, we performed RNA-sequencing and identified diurnal expression of core clock genes as well as clock-controlled genes in both sites. Interestingly, 20.1% and 30.4% of diurnal differentially expressed genes (DEGs) overlapped with paclitaxel-induced DEGs in the DRG and the DH respectively. In contrast, paclitaxelinduced DEGs displayed only a modest overlap between daytime and nighttime (Zeitgeber Time 8 and 20). Furthermore, paclitaxel treatment induced de novo diurnal DEGs, suggesting reciprocal interaction of circadian rhythms and chemotherapy. Our study therefore demonstrates a circadian oscillation of CIPN and its underlying transcriptomic landscape. Numerous vital processes in our body display time-of-day dependent oscillation. Such daily rhythms of tissuespecific and systemic functions are driven by the endogenous circadian clock where cellular oscillators, containing interlocked transcriptional-translational loops composed of positive (CLOCK/NPAS2, BMAL1, RORs) and negative (PERIOD1/2 (PER1/2) and CRYPTOCHROME1/2 (CRY1/2

Morning Chronotype Decreases the Risk of Chemotherapy-Induced Peripheral Neuropathy in Women With Breast Cancer

“…Follow-up data for several years after completion of chemotherapy can be used to analyze the factors associated with chronic CIPN. Third, several previous studies have reported circadian rhythmicity in the symptoms of peripheral neuropathy, 27 28 which may have contributed to the association of chronotype with CIPN. In our study, the analysis related above could not be performed because the information on severity of CIPN by time of day was not collected.…”

Proteome and Network Analysis Provides Novel Insights Into Developing and Established Chemotherapy-Induced Peripheral Neuropathy

“…For microarray datasets (Bangash et al, 2018;Housley et al, 2020) the data was downloaded and analyzed with Transcriptome Analysis Console (TAC Ver 4.0, Thermo Fisher). For RNAseq data (Kim et al, 2020) and translating ribosome affinity purification (TRAP)-processed data (Megat et al, 2019) was directly accessed through the publication. Venn diagrams for 2-3 groups were generated with BioVenn (Hulsen et al, 2008), while those for four groups with InteractiveVenn (Heberle et al, 2015).…”

“…Moreover, the CTNNB1 network harbours proteins previously shown by us to be regulated in another neuropathy-model, i.e., evoked by spared-nerve-injury (SNI) (Rouwette et al, 2016;Barry et al, 2018). Examples (by gene name) include Hsp90b1, Pdia6, (Bangash et al, 2018;Housley et al, 2020;Kim et al, 2020) at peak-CIPN. (B) Venn Diagram for comparison with the regulated translatome following paclitaxel (Megat et al, 2019) at pre-CIPN.…”

“…Both genomics and transcriptomics are increasingly exploited in pain research to characterize global changes at multiple levels of the nociceptive system. In the case of CIPN, several studies have investigated changes in the transcriptome at the level of the dorsal root ganglia (DRG) in rodent models (Bangash et al, 2018;Megat et al, 2019;Housley et al, 2020;Kim et al, 2020). However, results at mRNA level correlate only up to 50% with factual levels of corresponding proteins, which renders the interpretation of results and identification of novel targets difficult (Liu et al, 2016;Reimegård et al, 2021).…”

Circadian Clock-Controlled Checkpoints in the Pathogenesis of Complex Disease

“…Mechanistically, BMAL1, CLOCK, PER1, and REV-ERBα contribute to neuropathic pain at evening and cluster headache at midnight ( Burish et al, 2019 ). Core clock genes are rhythmically expressed in neurons of the dorsal root ganglion ( Kim H. K. et al, 2020 ). A Per2 mutation abolishes the circadian rhythm of the inflammatory pain response (peak ZT4) ( Zhang et al, 2012b ).…”