Neutrophil extracellular traps as a unique target in the treatment of inflammatory pain.

Pain is a widespread motivation for seeking healthcare and stands as a substantial global public health concern. Despite comprehensive investigations into the mechanisms of pain sensitization induced by inflammation, efficacious treatments options remain scarce. Neutrophil extracellular traps (NETs) have been associated with the progression and tissue damage of diverse inflammatory diseases. This study aims to explore the impact of NETs on the progression of inflammatory pain and explore potential therapeutic approaches. Initially, we observed neutrophil infiltration and the formation of NETs in the left hind paw of mice with inflammatory pain induced by complete Freund's adjuvant (CFA). Furthermore, we employed the peptidyl arginine deiminase 4 (PAD4) inhibitor Cl-amidine (diluted at 50 mg/kg in saline, administered via tail vein injection once daily for three days) to impede NETs formation and administered DNase1 (diluted at 10 mg/kg in saline, once daily for three days) to break down NETs. We investigated the pathological importance of peripheral NETs formation in inflammatory pain and its influence on the activation of spinal dorsal horn microglia. The findings indicate that neutrophils infiltrating locally generate NETs, leading to an increased release of inflammatory mediators that worsen peripheral inflammatory reactions. Consequently, this results in the transmission of more harmful peripheral stimuli to the spinal cord, triggering microglial activation and NF-κB phosphorylation, thereby escalating neuroinflammation and fostering pain sensitization. Suppression of peripheral NETs can mitigate peripheral inflammation in mice with inflammatory pain, reverse mechanical and thermal hypersensitivity by suppressing microglial activation in the spinal cord, ultimately diminishing inflammatory pain. In conclusion, these discoveries propose that obstructing or intervening with NETs introduces a novel therapeutic avenue for addressing inflammatory pain.

IGF-1 Combined with OPN Promotes Neuronal Axon Growth in Vitro Through the IGF-1R/Akt/mTOR Signaling Pathway in Lipid Rafts.

This study aims to investigate the effect of insulin-like growth factor 1 (IGF-1) combined with osteopontin (OPN) on the protein expression levels and growth of neuronal axons and its possible mechanism. In this study, IGF-1 combined with OPN promoted neuronal axon growth through the IGF-1R/Akt/mTOR signaling pathway in lipid rafts, and the effect was better than that of either agent alone. This effect was suppressed when given the mTOR inhibitor rapamycin or the lipid raft cholesterol extraction agent methyl-ß-cyclodextrin (M-ß-CD). Rapamycin could inhibit the expression of phosphorylated ribosomal S6 protein (p-S6) and phosphorylated protein kinase B (p-Akt) and limit axon growth. In addition to the above effects, M-ß-CD significantly downregulated the expression of phosphorylated insulin-like growth factor 1 receptor (p-IR). To further investigate the changes in lipid rafts when stimulated by different recombinant proteins, membrane lipid rafts were isolated to observe the changes by western blot. The expression levels of insulin-like growth factor 1 receptor (IR) and P-IR in the IGF-1 combined with OPN group were the highest. When M-ß-CD was administered to the lipid rafts of neurons, the enrichment of IR by IGF-1 combined with OPN was weakened, and the p-IR was decreased. Our study found that IGF-1 combined with OPN could promote axon growth by activating the IGF-1R/Akt/mTOR signaling pathway in neuronal lipid rafts.

Vagus nerve stimulation mediates microglia M1/2 polarization via inhibition of TLR4 pathway after ischemic stroke.

Ischemic stroke is the leading cause of death and disability. Microglia are polarized toward the proinflammatory M1 phenotype and neuroprotective M2 phenotype after stroke and play an important role in the pathological process of ischemic stroke. Emerging research suggests that vagus nerve stimulation (VNS) can mediate microglia polarization after ischemic stroke and may serve as a potential treatment for ischemic stroke. However, the mechanism by which VNS mediates microglia polarization remains unclear. In this study, we aimed to investigate the underlying mechanism. Sprague-Dawley rats were randomly divided into the sham, ischemic stroke, ischemic stroke + VNS, ischemic stroke + VNS + lentivirus (LV)-TLR4 and ischemic stroke + VNS + LV-CON groups. LV was injected into the lateral ventricles of the rats 14 days before ischemic stroke surgery, and VNS was administered after 30 min of occlusion. We assessed the infarct volume, neurological scores, the TLR4/MyD88/NF-κB protein level and microglia polarization after 3 days of reperfusion. Our results revealed that VNS can promote M2 microglia polarization and inhibit M1 microglia polarization to alleviate brain injury via inhibition of the TLR4/MyD88/NF-κB pathway in microglia in the acute stage of stroke.

C1q/TNF-related protein 4 restores leptin sensitivity by downregulating NF-κB signaling and microglial activation.

OBJECTIVE: C1qTNF-related protein 4 (CTRP4) acts in the hypothalamus to modulate food intake in diet-induced obese mice and has been shown to exert an anti-inflammatory effect on macrophages. Since high-fat diet-induced microglial activation and hypothalamic inflammation impair leptin signaling and increase food intake, we aimed to explore the potential connection between the anorexigenic effect of CTRP4 and the suppression of hypothalamic inflammation in mice with DIO. METHODS: Using an adenovirus-mediated hypothalamic CTRP4 overexpression model, we investigated the impact of CTRP4 on food intake and the hypothalamic leptin signaling pathway in diet-induced obese mice. Furthermore, central and plasma proinflammatory cytokines, including TNF-α and IL-6, were measured by Western blotting and ELISA. Changes in the hypothalamic NF-κB signaling cascade and microglial activation were also examined in vivo. In addition, NF-κB signaling and proinflammatory factors were investigated in BV-2 cells after CTRP4 intervention. RESULTS: We found that food intake was decreased, while leptin signaling was significantly improved in mice with DIO after CTRP4 overexpression. Central and peripheral TNF-α and IL-6 levels were reduced by central Ad-CTRP4 administration. Hypothalamic NF-κB signaling and microglial activation were also significantly suppressed in vivo. In addition, NF-κB signaling was inhibited in BV-2 cells following CTRP4 intervention, which was consistent with the decreased production of TNF-α and IL-6. CONCLUSIONS: Our data indicate that CTRP4 reverses leptin resistance by inhibiting NF-κB-dependent microglial activation and hypothalamic inflammation.

MPPa-PDT suppresses breast tumor migration/invasion by inhibiting Akt-NF-κB-dependent MMP-9 expression via ROS.

BACKGROUND: Breast cancer is one of the most commonly diagnosed cancers in women, with high morbidity and mortality. Tumor metastasis is implicated in most breast cancer deaths; thus, inhibiting metastasis may provide a therapeutic direction for breast cancer. In the present study, pyropheophorbide-α methyl ester-mediated photodynamic therapy (MPPa-PDT) was used to inhibit metastasis in MCF-7 breast cancer cells. METHODS: Uptake of MPPa was detected by fluorescence microscopy. Cell viability was evaluated by the Cell Counting Kit-8 (CCK-8). ROS generation was detected by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). The migration of cells was assessed by wound healing assay, and invasion ability was assessed by Matrigel invasion assay. Levels of MMP2 and MMP9 were measured by PCR. Akt, phospho-Akt (Ser473), phospho-NF-κB p65 (Ser536) and NF-κB p65 were measured by western blotting. The F-actin cytoskeleton was observed by immunofluorescence. Lung tissue was visualized by hematoxylin and eosin staining. RESULTS: Following MPPa-PDT, migration and invasion were decreased in the MCF-7 cells. MPPa-PDT downregulated the expression of MMP2 and MMP9, which are responsible for the initiation of metastasis. MPPa-PDT reduced the phosphorylation of Akt and NF-κB. MPPa-PDT also reduced the expression of F-actin in cytoskeleton in MCF-7 cells. These effects were blocked by the reactive oxygen species scavenger NAC or the Akt activator SC79, while the PI3K inhibitor LY294002 or the Akt inhibitor triciribine enhanced these effects. Moreover, MPPa-PDT inhibited tumor metastasis and destroyed F-actin in vivo. CONCLUSION: Taken together, these results demonstrate that MPPa-PDT inhibits the metastasis of MCF-7 cells both in vitro and in vivo and may be involved in the Akt/NF-κB-dependent MMP-9 signaling pathway. Thus, MPPa-PDT may be a promising treatment to inhibit metastasis.

Effects of kinesiotape on pain and disability in individuals with chronic low back pain: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE:: To explore the effects of kinesiotape on pain and disability in individuals with chronic low back pain. DATA SOURCES:: PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched for English language publications from inception to 13 February 2018. REVIEW METHODS:: This study was registered in PROSPERO (CRD42018089831). Our key search terms were ((kinesio taping) OR (kinesiotaping) OR (kinesiotape)) AND (low back pain). Randomized controlled trials evaluating the effects of kinesiotape published in English language were included in this review. The reference lists of retrieved studies and relevant reviews were also searched. Quality of the included trials was assessed according to 2015 updated Cochrane Back and Neck Review Group 13-Item criteria. RESULTS:: A total of 10 articles were included in this meta-analysis. A total of 627 participants were involved, with 317 in the kinesiotape group and 310 in the control group. The effects of kinesiotape on pain and disability were explored. While kinesiotape was not superior to placebo taping in pain reduction, either alone ( P = 0.07) or in conjunction with physical therapy ( P = 0.08), it could significantly improve disability when compared to the placebo taping ( P < 0.05). CONCLUSION:: Since kinesiotape is convenient for application, it could be used for individuals with chronic low back pain in some cases, especially when the patients could not get other physical therapy.

Environmental Enrichment Improves Spatial Learning and Memory in Vascular Dementia Rats with Activation of Wnt/ß-Catenin Signal Pathway.

BACKGROUND Environmental enrichment (EE) has a beneficial effect on some neuropsychiatric disorders. In this study, we aimed to investigate whether environmental enrichment could improve the spatial learning and memory in rats with vascular dementia (VaD) and the mechanism underpinning it. MATERIAL AND METHODS Bilateral common carotid occlusion (2-vessel occlusion [2VO]) was used to develop the animal model of vascular dementia. Adult male Sprague-Dawley (SD) rats were used in the experiment and were randomly divided into 4 groups: sham group, 2VO group, sham+EE group, and 2VO+EE group (n=19/group). The 2VO group and 2VO+EE group underwent bilateral common carotid occlusion. Two different housing conditions were used in this experiment: standard environment (SE) and enriched environment (EE). Rats in the sham group and 2VO group were put into SE cages for 4 weeks, while rats in the sham+EE group and 2VO+EE group were put in EE cages for 4 weeks. The Morris water maze and Y-maze were used to assess spatial learning and memory. Apoptosis was detected by TUNEL. The damage of neurons in the hippocampus was assessed by Nissl staining. The level of wnt pathway proteins were detected by Western blot. RESULTS Compared with the 2VO group, the rats in the 2VO+EE group had better behavioral performance, fewer apoptotic neurons, and more surviving neurons. Western blot analysis showed that the levels of wnt pathway proteins were higher in 2VO+EE rats than in the 2VO group. CONCLUSIONS Environmental enrichment can improve the spatial learning and memory in rats with vascular dementia, and the mechanism may be related to activation of the wnt/ß-catenin signal pathway.

The sensitivity of glioma cells to pyropheophorbide-αmethyl ester-mediated photodynamic therapy is enhanced by inhibiting ABCG2.

BACKGROUND AND OBJECTIVE: To study the mechanisms of human glioblastoma cell resistance to methyl ester pyropheophorbide-a-mediated photodynamic therapy (MPPa-PDT) and the relationship between the cells and adenosine triphosphate-binding cassette superfamily G member 2 (ABCG2). STUDY DESIGN/MATERIALS AND METHODS: The sensitivity of four human glioma cell lines (U87, A172, SHG-44, and U251) to MPPa-PDT was detected with a CCK-8 assay. Cell apoptosis, intracellular MPPa, and singlet oxygen were tested with flow cytometry. The mRNA and protein expression of ATP-binding cassette transporters (ABCG2, MRP1, and MDR1) were detected by PCR and Western blot, respectively. RESULTS: Both the sensitivity to MPPa-PDT and intracellular MPPa in A172 were the lowest among the four cell lines, while expression of ABCG2 mRNA and protein in A172 were the highest. The intracellular MPPa and ROS in A172 receiving MPPa-PDT significantly increased after using the ABCG2 inhibitor fumitremorgin C (FTC). Both cell viability and apoptosis in A172 cells undergoing MPPa-PDT were significantly improved with FTC. CONCLUSIONS: ABCG2 plays a significant role in the resistance of A172 to MPPa-PDT. Lasers Surg. Med. 49:719-726, 2017. © 2017 Wiley Periodicals, Inc.

Musculoskeletal Ultrasound: A Novel Approach for Luschka's Joint and Vertebral Artery.

BACKGROUND: Cervical vertigo has been a controversial diagnosis for several years, and the lack of a diagnostic test is a critical problem. Musculoskeletal ultrasound (MSUS) is a real-time dynamic approach that is used to investigate the musculoskeletal and vascular systems. MATERIAL/METHODS: In this study, MSUS was used to examine whether there is a relationship among vertigo, the vertebral artery (VA), and Luschka's joint proliferation in patients with cervical vertigo. RESULTS: MSUS clearly revealed the size, shape, and characteristics of the Luschka's joint, the VA, and the surrounding structures. The Luschka's joint proliferation was not distributed uniformly, but the predilection sites were C4/5 (50.5%) and C5/6 (32.3%). The proliferation from C4/5 and C5/6 Luschka's joints was the major cause of the grade 2/3 VA tortuosity. Moreover, there was a significant correlation between VA compression from Luschka's joint proliferation and the symptoms of cervical vertigo. CONCLUSIONS: MSUS is a real-time and noninvasive technique that can be used to locate and observe Luschka's joint and the VA during research and clinical applications. In future practice MSUS could be used as a diagnostic approach for patients with suspected cervical vertigo.

A Novel Passive Wireless Sensor for Concrete Humidity Monitoring.

This paper presents a passive wireless humidity sensor for concrete monitoring. After discussing the transmission of electromagnetic wave in concrete, a novel architecture of wireless humidity sensor, based on Ultra-High Frequency (UHF) Radio Frequency Identification (RFID) technology, is proposed for low-power application. The humidity sensor utilizes the top metal layer to form the interdigitated electrodes, which were then filled with polyimide as the humidity sensing layer. The sensor interface converts the humidity capacitance into a digital signal in the frequency domain. A two-stage rectifier adopts a dynamic bias-voltage generator to boost the effective gate-source voltage of the switches in differential-drive architecture. The clock generator employs a novel structure to reduce the internal voltage swing. The measurement results show that our proposed wireless humidity can achieve a high linearity with a normalized sensitivity of 0.55% %RH at 20 °C. Despite the high losses of concrete, the proposed wireless humidity sensor achieves reliable communication performances in passive mode. The maximum operating distance is 0.52 m when the proposed wireless sensor is embedded into the concrete at the depth of 8 cm. The measured results are highly consistent with the results measured by traditional methods.

A randomized controlled trial of low-frequency repeated transcranial magnetic stimulation in patients with poststroke neurogenic bladder.

Urinary incontinence is a common complication in stroke survivors for whom new interventions are needed. This study investigated the therapeutic effect of low-frequency (LF) repeated transcranial magnetic stimulation (rTMS) on the contralesional primary motor cortex (M1) in patients with poststroke urinary incontinence (PSI). A total of 100 patients were randomly assigned to the rTMS group or sham-rTMS group on basis of the intervention they received. Both groups underwent five treatment sessions per week for 4 weeks. Data from the urodynamic examination were used as the primary outcome. The secondary outcome measures were questionnaires and pelvic floor surface electromyography. After 4 weeks of intervention, the maximum cystometric capacity (MCC), maximum detrusor pressure (Pdet.max), residual urine output, overactive bladder score (OABSS) (including frequency, urgency, and urgency urinary incontinence), and the ICIQ-UI SF improved significantly in the rTMS group compared with those in the sham-rTMS group (P < 0.05). However, no changes in pelvic floor muscle EMG were detected in patients with PSI (both P > 0.05). Our data confirmed that 4 weeks of LF-rTMS stimulation on the contralateral M1 positively affects poststroke urinary incontinence in several aspects, such as frequency, urgency urinary incontinence, MCC, end-filling Pdet, OABSS, and ICIQ-UI SF scores.

Low-Dose LPS Modulates Microglia/Macrophages Phenotypic Transformation to Amplify Rehabilitation Effects in Chronic Spinal Cord Injured (CSCI) Mice.

Spinal cord injury (SCI) results in stalled motor function recovery under the chronic phase. One of the reasons due to the presence of ongoing inflammation. Therefore, regulating the status of immune cells may help reopen the window for neural repair, which represents a potential therapeutic target. In this study, we aimed to investigate whether this could be achieved in mice with cervical 5 crush CSCI (4 W) by utilizing a concentration of 0.5 mg/kg of lipopolysaccharide (LPS) to stimulate microglia/macrophages. Additionally, the mice underwent rehabilitation training for another 6 weeks. Our results showed that systemic injection of LPS enhanced the effects of forelimb rehabilitation training, as evaluated through single pellet grasping (SPG). Electrophysiological studies revealed the restoration of cortical drive to the injured side's forelimb muscles in the training combined with LPS group. Tract tracing studies demonstrated the reconstruction of cortical innervation to the cervical spinal cord. Furthermore, the levels of pro-inflammatory phenotype markers, such as inducible nitric oxide synthase (INOS) and CD68, decreased, while the expression of anti-inflammatory phenotype markers, including arginase 1 (ARG-1) and CD206, increased. Importantly, this phenotypic switch in microglia/macrophages was accompanied by an increase in phagocytic activity markers as indicated by BODIPY + IBA1 + staining. Collectively, our data suggests that low-dose LPS improves the effects of rehabilitation training by regulating the phenotypic transformation of microglia/macrophages in CSCI. This study provides a fresh perspective and intervention direction for the clinical treatment of chronic spinal cord injuries.

An Acute Bout of Exercise Suppresses Appetite via Central Lactate Metabolism.

Exercise has been reported to elicit a transient suppression of appetite. Plasma lactate, which is produced by exercising muscle, is believed to have a critical effect on exercise-induced appetite suppression. However, the underlying mechanisms and signaling steps of central lactate metabolism remain unexplored. After central oxamate administration, C57BL/6J male mice performed 10 high-intensity interval running at 90% Vmax for 4 minutes each, which separated by 2 minutes at 12 m/min. Food intake and the expression of hypothalamic appetite-regulating neuropeptides including proopiomelanocortin (POMC) and neuropeptide Y (NPY) were investigated following exercise training. Janus kinase 2 (Jak2)-signal transducer and activator of transcription 3 (STAT3) signaling pathway was also determined by Western blot. In addition, hypoxia-inducible factor-1α (HIF-1α) was investigated to explore the effect of central lactate metabolism following exercise. We found that central oxamate administration reversed exercise-induced suppression of food intake, and as well as changes in the expression of POMC and NPY. Moreover, acute exercise led to an increase in the phosphorylation of Jak2 and STAT3 in the hypothalamus, while central lactate inhibition significantly blunted this effect. In addition, HIF-1α expression increased obviously after exercise, while it was attenuated by central oxamate administration. Collectively, our data reveal that central lactate metabolism mediates exercise-induced suppression of appetite and changes in neuropeptides, possibly through enhanced Jak2-STAT3 signaling.

Focused low-intensity pulsed ultrasound alleviates osteoarthritis via restoring impaired FUNDC1-mediated mitophagy.

Mitophagy is critical for maintaining proper cellular functions, and it contributes to the onset and progression of osteoarthritis (OA). A recent study showed that focused low-intensity pulsed ultrasound (FLIPUS) could activate mitophagy, but the molecular mechanism remains unclear. This study aimed to elucidate the chondroprotective effects of FLIPUS in OA and the regulatory effects on FUN14-domain containing 1 (FUNDC1-mediated mitophagy. In vitro, FLIPUS improved inflammatory response, anabolism, and catabolism in interleukin (IL)-1ß-induced OA chondrocytes. The chondroprotective effects of FLIPUS were attributed to promoting the expression of phosphoglycerate mutase 5 (PGAM5) and the dephosphorylation of FUNDC1 at serine 13 (Ser13), as well as promoting the mitophagy process. In vivo, FLIPUS reduced the cartilage degeneration and apoptosis and reversed the change of anabolic- and catabolic-related proteins in destabilized medial meniscus (DMM)-induced mouse model. Thus, the study indicates that FLIPUS exhibits a chondroprotective effect via activating impaired FUNDC1-mediated mitophagy.

Erratum: [Corrigendum] Lidocaine inhibits the invasion and migration of TRPV6­expressing cancer cells by TRPV6 downregulation.

[This corrects the article DOI: 10.3892/ol.2016.4709.].

Vagus nerve stimulation is a potential treatment for ischemic stroke.

Microglia are the brain's primary innate immune cells, and they are activated and affect pro-inflammatory phenotype or regulatory phenotype after ischemic stroke. Vagus nerve stimulation was shown to activate microglial phenotypic changes and exhibit neuroprotective effects in ischemia/reperfusion injury. In this study, we established rat models of ischemic stroke by occlusion of the middle cerebral artery and performed vagus nerve stimulation 30 minutes after modeling. We found that vagus nerve stimulation caused a shift from a pro-inflammatory phenotype to a regulatory phenotype in microglia in the ischemic penumbra. Vagus nerve stimulation decreased the levels of pro-inflammatory phenotype markers inducible nitric oxide synthase and tumor necrosis factor α and increased the expression of regulatory phenotype markers arginase 1 and transforming growth factor ß through activating α7 nicotinic acetylcholine receptor expression. Additionally, α7 nicotinic acetylcholine receptor blockade reduced the inhibition of Toll-like receptor 4/nuclear factor kappa-B pathway-associated proteins, including Toll-like receptor 4, myeloid differentiation factor 88, I kappa B alpha, and phosphorylated-I kappa B alpha, and also weakened the neuroprotective effects of vagus nerve stimulation in ischemic stroke. Vagus nerve stimulation inhibited Toll-like receptor 4/nuclear factor kappa-B expression through activating α7 nicotinic acetylcholine receptor and regulated microglial polarization after ischemic stroke, thereby playing a role in the treatment of ischemic stroke. Findings from this study confirm the mechanism underlying vagus nerve stimulation against ischemic stroke.

Moderate-Intensity Treadmill Exercise Promotes mTOR-Dependent Motor Cortical Neurotrophic Factor Expression and Functional Recovery in a Murine Model of Crush Spinal Cord Injury (SCI).

Treadmill exercise is widely considered an effective strategy for restoration of skilled motor function after spinal cord injury (SCI). However, the specific exercise intensity that optimizes recovery and the underlying mechanistic basis of this recovery remain unclear. To that end, we sought to investigate the effect of different treadmill exercise intensities on cortical mTOR activity, a key regulator of functional recovery following CNS trauma, in an animal model of C5 crush spinal cord injury (SCI). Following injury, animals were subjected to treadmill exercise for 4 consecutive weeks at three different intensities (low intensity [LEI]; moderate intensity [MEI]; and high intensity [HEI]). Motor function recovery was assessed by horizontal ladder test, cylinder rearing test, and electrophysiology, while neurotrophic factors and cortical mechanistic target of rapamycin (mTOR) pathway-related proteins were assessed by Western blotting. The activation of the cortical mTOR pathway and axonal sprouting was evaluated by immunofluorescence and the changes of plasticity in motor cortex neurons were assessed by Golgi staining. In keeping with previous studies, we found that 4 weeks of treadmill training resulted in improved skilled motor function, enhanced nerve conduction capability, increased neuroplasticity, and axonal sprouting. Importantly, we also demonstrated that when compared with the LEI group, MEI and HEI groups demonstrated elevated expression of brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), phosphorylated ribosomal S6 protein (p-S6), and protein kinase B (p-Akt), consistent with an intensity-dependent activation of the mTOR pathway and neurotrophic factor expression in the motor cortex. We also observed impaired exercise endurance and higher mortality during training in the HEI group than in the LEI and MEI groups. Collectively, our findings suggest that treadmill exercise following SCI is an effective means of promoting recovery and highlight the importance of the cortical mTOR pathway and neurotrophic factors as mediators of this effect. Importantly, our findings also demonstrate that excessive exercise can be detrimental, suggesting that moderation may be the optimal strategy. These findings provide an important foundation for further investigation of treadmill training as a modality for recovery following spinal cord injury and of the underlying mechanisms.

Genetic polymorphisms of PRKAA1 (AMPKα1) and postherpetic pain susceptibility: Multicenter, randomized control, and haplotype analysis study.

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a pivotal regulatory protein in energy metabolism. In a pilot study, we found that AMPK-associated energy metabolism imbalance in neurons contributes to the occurrence and maintenance of neuropathic pain (NeP). This study aimed to explore the relationship between genetic polymorphisms of AMPK gene (Rs13361707, rs3792822, and rs10074991) in PRKAA1 and postherpetic neuralgia (PHN) in Chinese individuals. Hundred and thirty two patients with PHN and 118 control individuals were enrolled in this study. All blood samples were shuffled and blinded to the person performing the haplotype analysis. Rs13361707, rs3792822, and rs10074991 PRKAA1 genotypes were identified in all participants. Dominant and recessive models were used for evaluating the association between these nucleotide polymorphisms and PHN susceptibility. A haplotype analysis of PHN patients and healthy controls was performed. Clinical characteristics between the two groups were not significantly different (p > 0.05) except that the ages in control subjects were younger than the PHN patients (p < 0.05). Genotypes and allele frequencies are significantly different between the PHN patients and control subjects for the rs13361707 and rs10074991 polymorphisms (p < 0.05), but not for rs3792822 (p > 0.05). In addition, the CCG haplotype of rs13361707-rs3792822-rs10074991 correlated negatively with PHN occurrence, but TCA was positively correlated with PHN (p < 0.05). Our results indicate that PRKAA1 gene polymorphisms rs13361707 and rs10074991 were associated with a risk of PHN, and that the CCG haplotype of rs13361707-rs3792822-rs10074991 correlated negatively with PHN occurrence in haplotype analysis. TCA was positively associated with PHN in Chinese individuals.

Effects of task-based rehabilitative training combined with PTEN/SOCS3 coinhibition promotes axon regeneration and upper extremity skilled motor function recovery after cervical spinal cord injury in adult mice.

Previous studies reported that the codeletion of PTEN and SOCS3 can greatly enhance the capacity of axon regeneration after central nervous system (CNS) injury. Moreover, the promotion of functional recovery can be improved by rehabilitative training under a use-dependent plasticity mechanism after CNS injury. However, few studies have reported the interaction between these mechanisms after spinal cord injury (SCI). Therefore, we investigated the combined effects of PTEN/SOCS3 coinhibition and rehabilitative training on axon regeneration and upper extremity motor functional improvement after cervical SCI in mice. In this study, we used RNA interference viruses to coinhibit PTEN and SOCS3 and induced a C5 crush injury on the side of preference. The injured upper extremity was trained by single pellet grasping for 4 weeks. We found that the coinjection of viruses significantly increased the expression of p-S6 and p-STAT in the cortex, reduced the dieback pattern of injured axons and promoted traced axon regeneration. More importantly, combination therapy further enhanced axon regeneration compared with PTEN/SOCS3 coinhibition alone. In behavioral tests, the motor performance of the mice in the PTEN/SOCS3 + Training group was better than that of the mice in the other groups. These results indicate that combining task-based rehabilitative training with PTEN/SOCS3 coinhibition further promotes axon regeneration and significant improvement in forelimb skilled motor function after cervical SCI. Our findings provide new therapeutic insights into SCI treatment.

Osteopontin enhances the effect of treadmill training and promotes functional recovery after spinal cord injury.

In this study, we examined the combined impact of osteopontin (OPN) and treadmill training on mice with spinal cord injury (SCI). OPN was overexpressed by injecting AAV9-SPP1-GFP into the sensorimotor cortex, followed by a left incomplete C5 crush injury two weeks later. Mice (Ex or Ex + OPN group) were trained at 50% maximum running speed for 8 weeks. To analyze the effects, we used biotinylated dextran amine (BDA) for tracing the corticospinal tract (CST) and performed Western blotting and immunohistochemical methods to assess the activation of the mammalian target of rapamycin (mTOR). We also examined axonal regeneration and conducted behavioral tests to measure functional recovery. The results demonstrated that treadmill training promoted the expression of neurotrophic factors such as brain-derived neurotrophic factor (BNDF) and insulin-like growth factor I (IGF-1) and activated mTOR signaling. OPN amplified the effect of treadmill training on activating mTOR signaling indicated by upregulated phosphorylation of ribosomal protein S6 kinase (S6). The combination of OPN and exercise further promoted functional recovery and facilitated limited CST axonal regeneration which did not occur with treadmill training and OPN treatment alone. These findings indicate that OPN enhances the effects of treadmill training in the treatment of SCI and offer new therapeutic insights for spinal cord injury.