The role of autophagic kinases in regulation of axonal function

Guizhi Fuling capsules can alleviate bortezomib-induced peripheral neuropathy by decreasing Interleukin-6 levels to regulate mTOR pathway-induced autophagy

OBJECTIVE

To investigate the therapeutic effect and underlying mechanism of Guizhi Fuling capsule (GZFL) on bortezomib-induced peripheral neuropathy (BiPN).

MATERIALS AND METHODS

Interleukin-6 (IL-6) levels in the plasma of Multiple myeloma (MM) patients were measured by ELISA, and correlation analysis between IL-6 and clinical features of BiPNs was performed. Then, we assess the clinical therapeutic effects of GZFL on MM patients by detecting IL-6 level, PN grade, FACT score, VAS score, MVC and SCV before and after the treatment. A combination of LC/MS and network pharmacology analysis was used to investigate the components and targets of GZFL. Then, bioinformatics was carried out. After PC12 cells were treated with GZFL, a BiPN cell model was constructed to evaluate cell autophagy function by cell viability, IL-6 levels, ROS levels, immunofluorescence staining of LC3 puncta, electron transmission electron microscopy (TEM), and Western blotting (WB). C57BL/6 mice were administered bortezomib by intraperitoneal injection to establish a model of BiPN. Nerve injury in BiPN mice was observed by measuring ethology, motor nerve conduction velocity, and IL-6. ROS, HE staining. TEM, western blotting and IHC were used to detect the expression of autophagy-related indexes.

RESULTS

In BiPN patients, IL-6 levels were positively correlated with the PN and FACT, VAS scores. Collectively, GZFL can alleviate BiPN by reducing the level of IL-6, which is mainly manifested in the decline of PN grade, FACT, VAS score and the improvement of MVC and SCV. Thirty-four components and 107 targets of GZFL for BiPN were obtained. IL-6, mTOR, and AKT1 showed high degree values, and the significantly enriched signaling pathways were closely related to inflammatory factors and autophagy pathways, such as TNF and the mTOR signaling pathway. GZFL significantly decreased IL-6 levels in cell and animal models of BiPN. For the autophagy test, GZFL increased PC12 cell ability and the numbers of LC3 puncta and autophagic vesicles after bortezomib treatment. In vivo experiments showed that GZFL effectively improved the behavior of mice with BiPN and alleviated sciatic nerve injury. WB and IHC showed that GZFL enhanced autophagy, as indicated by the alteration of autophagy-related protein levels in PC12 cells and sciatic nerve tissue.

CONCLUSION

The present study confirmed that GZFL significantly ameliorates peripheral neuropathy by regulating autophagy levels via alleviating high levels of IL-6 .

TRIAL REGISTRATION

The link to the registration: Chinese Clinical Trial Registry (https://www.chictr.org.cn/bin/project/edit?pid=214832). The name of the trial register is "The role of mitochondrial autophagy in multiple myeloma peripheral neuropathy and the application of traditional Chinese medicine for warming Yang and removing blood stasis". The clinical trial registration number is ChiCTR2400088065.

Axonopathy Underlying Amyotrophic Lateral Sclerosis: Unraveling Complex Pathways and Therapeutic Insights

Amyotrophic Lateral Sclerosis (ALS) is a complex neurodegenerative disorder characterized by progressive axonopathy, jointly leading to the dying back of the motor neuron, disrupting both nerve signaling and motor control. In this review, we highlight the roles of axonopathy in ALS progression, driven by the interplay of multiple factors including defective trafficking machinery, protein aggregation, and mitochondrial dysfunction. Dysfunctional intracellular transport, caused by disruptions in microtubules, molecular motors, and adaptors, has been identified as a key contributor to disease progression. Aberrant protein aggregation involving TDP-43, FUS, SOD1, and dipeptide repeat proteins further amplifies neuronal toxicity. Mitochondrial defects lead to ATP depletion, oxidative stress, and Ca2+ imbalance, which are regarded as key factors underlying the loss of neuromuscular junctions and axonopathy. Mitigating these defects through interventions including neurotrophic treatments offers therapeutic potential. Collaborative research efforts aim to unravel ALS complexities, opening avenues for holistic interventions that target diverse pathological mechanisms.

Current potential pathogenic mechanisms of copper-zinc superoxide dismutase 1 (SOD1) in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease which damages upper and lower motor neurons (UMN and LMN) innervating the muscles of the trunk, extremities, head, neck and face in cerebrum, brain stem and spinal cord, which results in the progressive weakness, atrophy and fasciculation of muscle innervated by the related UMN and LMN, accompanying with the pathological signs leaded by the cortical spinal lateral tract lesion. The pathogenesis about ALS is not fully understood, and no specific drugs are available to cure and prevent the progression of this disease at present. In this review, we reviewed the structure and associated functions of copper-zinc superoxide dismutase 1 (SOD1), discuss why SOD1 is crucial to the pathogenesis of ALS, and outline the pathogenic mechanisms of SOD1 in ALS that have been identified at recent years, including glutamate-related excitotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, oxidative stress, axonal transport disruption, prion-like propagation, and the non-cytologic toxicity of glial cells. This review will help us to deeply understand the current progression in this field of SOD1 pathogenic mechanisms in ALS.