Management of Neuropathic Pain in the Geriatric Population

Silencing of FTO inhibits oxidative stress to relieve neuropathic pain by m6A modification of GPR177

BACKGROUND

Neuropathic pain (NP) is a challenging health condition owing to its complex nature and associated multiple etiologies. The occurrence of NP involves the abnormal activity of neurons mediated by oxidative stress (OS). Previous research has demonstrated that m6A methylation plays a role in the regulatory pathway of NP. This study aimed to investigate the specific molecular pathways through which m6A methylation modifiers alleviate NP.

METHODS

For this purpose, an NO rat model was developed via spared nerve injury (SNI), followed by quantifying the animal's pain assessment via paw withdrawal threshold (PWT) and paw withdrawal latency (PWL). The OS in SNI rats was evaluated by measuring reactive oxygen species, superoxide dismutase, and catalase (CAT) in spinal cord tissues. Moreover, quantitative-real-time polymerase chain reaction and western blot analysis were employed for detecting fat mass and obesity-associated (FTO) and GPR177 levels, while m6A levels of GPR117 were analyzed via MeRIP.

RESULTS

The results indicated an enhanced OS with highly expressed FTO in spinal cord tissue samples, where knocking down Fto effectively relieved NP and OS in SNI rats. Mechanistic investigations revealed that Fto-mediated reduction of Grp177 m6A modification was involved in the WNT5a/TRPV1 axis-mediated OS remission of NP. Moreover, in vitro experiment results indicated that YTHDF2 was an important m6A methylated reading protein for this process.

CONCLUSIONS

Fto silencing leads to increased m6A methylation of Grp177 through a YTHDF2-dependent mechanism, resulting in decreased Grp177 stability and ultimately reducing NP in rats by OS suppression.

Long noncoding RNA small nucleolar RNA host gene 5 facilitates neuropathic pain in spinal nerve injury by promoting SCN9A expression via CDK9

This study aims to explore the functions and mechanisms of long noncoding RNA small nucleolar RNA host gene 5 (SNHG5) in chronic constriction injury (CCI)-induced neuropathic pain (NP). An NP rat model was established using the CCI method and the NP severity was evaluated by paw withdrawal threshold (PWT) and paw withdrawal latency (PWL). The expression of SNHG5, CDK9, and SCN9A was quantified in rat dorsal root ganglion, in addition to the detections of apoptosis, pathological changes, neuron number, and the co-localization of Nav1.7 and cleaved caspase-3 with NeuN. In ND7/23 cells, the apoptosis and lactate dehydrogenase concentration were assessed, as well as the relationship between SNHG5, CDK9, and SCN9A. In the dorsal root ganglion of CCI-treated rats, SNHG5 and SCN9A were upregulated and downregulation of SNHG5 suppressed SCN9A expression, increased the PWT and PWL, blocked neuroinflammation and neuronal apoptosis, and alleviated NP. Mechanistically, SNHG5 recruited CDK9 to enhance SCN9A-encoded Nav1.7 expression and promoted peripheral neuronal apoptosis and injury. In addition, SCN9A overexpression nullified the alleviative effects of SNHG5 deficiency on NP and neuron loss in CCI rats. In conclusion, SNHG5 promotes SCN9A-encoded Nav1.7 expression by recruiting CDK9, thereby facilitating neuron loss and NP after spinal nerve injury, which may offer a promising target for the management of NP.

"Emerging Topics in Pain Medicine": Advancing Research and Patient-Centered Health Strategies

Pain, in all its various forms and manifestations, impacts the lives of millions worldwide [...].