Elastin expression in the conjoint fascial sheath and levator palpebrae superioris muscle of children with unilateral severe congenital ptosis with different muscle strengths.

Elastin expression in the conjoint facial sheath (CFS) of patients of different ages with severe ptosis has been extensively studied, but its expression in the CFS of pediatric patients with severe ptosis with different muscle strengths remains poorly understood. The aim of the present study was to investigate the expression of elastin in the CFS and levator palpebrae superioris muscle (LM) of children with severe congenital ptosis with different LM strengths. In total, 20 pediatric patients with unilateral severe congenital ptosis (20 eyes) were included, who underwent CFS + LM complex suspension surgery from June 2020 to February 2022. Among these patients, the LM strength was 0-1 mm in 10 patients and 2-3 mm in the other 10 patients. Excess CFS and LM tissue samples were obtained from the patients during surgery, before the protein expression levels of elastin in the specimens were measured by western blotting. During the 6-month postoperative follow-up period, the good correction rate, the degree of incomplete eyelid closure and the incidence of complications were observed. Western blotting results showed that, compared with that in the 0-1 mm group, elastin expression was not significantly different in the CFS, whereas it was significantly increased (P=0.021) in the LM of the 2-3 mm group. In addition, elastin expression in the CFS was markedly higher compared with that in the LM in both groups (in the 0-1 mm group, P=0.005; in the 2-3 mm group, P=0.009). Additionally, the curative effect evaluation revealed that the good correction rates in the 0-1 and 2-3 mm groups were 90 and 100%, respectively. In total, 3 patients experienced conjunctival prolapse during the follow-up period, including 2 patients in the 0-1 mm group and 1 patient in the 2-3 mm group, but there were no other complications. To conclude, elastin expression in the CFS was found to be higher compared with that in the LM of children with severe congenital ptosis. Although elastin expression in the LM was positively associated with LM strength, its expression in the CFS displayed no clear association with LM function. Therefore, these observations suggested that CFS + LM complex suspension surgery is viable to correct severe congenital ptosis in pediatric patients.

An antibacterial packaging film based on amylose starch with quaternary ammonium salt chitosan and its application for meat preservation.

A new generation of food packaging films is gradually replacing traditional plastic packaging films because of their biodegradability, safety, and some functional properties such as anti-bacterial and oxidant resistance. In the present work, an antibacterial packing film based on amylose starch and 2-hydroxypropyl-trimethylammonium chloride chitosan (HTCC) was prepared for meat preservation. The interfacial bonding mechanism between amylose, HTCC, and glutaraldehyde (GA) was determined experimentally and through molecular dynamics (MD) simulation. The macromolecular chains of amylose starch and HTCC became entangled via inter-molecular H-bonds and then cross-linked with GA via the Schiff base reaction. The interaction of amylose starch and HTCC improved the mechanical properties of the amylose films. Compared with the amylose films, the tensile strength and elongation at break of the optimal HTCC/amylose films reached to 16.13 MPa (an increase of 206.65 %) and 53.86 % (an increase of 109.49 %). The HTCC/amylose films were found to provide obvious bacteriostatic performance, a relatively low cytotoxicity, the lower transmittance in the UV region, and thus the ability to enhance the preservation of fresh meat. These excellent characteristics therefore suggest that HTCC/amylose films might be promising candidates for application in antibacterial food packaging films.

Transcription factor EBF1 mitigates neuropathic pain by rescuing Kv1.2 expression in primary sensory neurons.

Nerve injury-induced alternations of gene expression in primary sensory neurons of the dorsal root ganglion (DRG) are molecular basis of neuropathic pain genesis. Transcription factors regulate gene expression. In this study, we examined whether early B cell factor 1 (EBF1), a transcription factor, in the DRG, participated in neuropathic pain caused by chronic constriction injury (CCI) of the sciatic nerve. EBF1 was distributed exclusively in the neuronal nucleus and coexpressed with cytoplasmic/membrane Kv1.2 in individual DRG neurons. The expression of Ebf1 mRNA and protein was time-dependently downregulated in the ipsilateral lumbar (L) 3/4 DRGs after unilateral CCI. Rescuing this downregulation through microinjection of the adeno-associated virus 5 expressing full-length Ebf1 mRNA into the ipsilateral L3/4 DRGs reversed the CCI-induced decrease of DRG Kv1.2 expression and alleviated the development and maintenance of mechanical, heat and cold hypersensitivities. Conversely, mimicking the downregulation of DRG EBF1 through microinjection of AAV5-expressing Ebf1 shRNA into unilateral L3/4 DRGs produced a reduction of Kv1.2 expression in the ipsilateral L3/4 DRGs, spontaneous pain, and the enhanced responses to mechanical, heat and cold stimuli in naive mice. Mechanistically, EBF1 not only bound to the Kcna2 gene (encoding Kv1.2) promoter but also directly activated its activity. CCI decreased the EBF1 binding to the Kcna2 promoter in the ipsilateral L3/4 DRGs. Our findings suggest that DRG EBF1 downregulation contributes to neuropathic pain likely by losing its binding to Kcna2 promoter and subsequently silencing Kv1.2 expression in primary sensory neurons. Exogenous EBF1 administration may mitigate neuropathic pain by rescuing DRG Kv1.2 expression.

Effect of Sepiolite on the Field-Dependent Normal Force of Magnetorheological Grease.

In order to investigate the influence of sepiolite minerals on the normal force of magnetorheological grease (MRG), a mixed sample (ALCH) on the basis of preparing an aluminum-lithium-based magnetorheological grease (base sample ALC), containing sepiolite was further prepared. The field-dependent normal force of the two samples was tested using a rotational rheometer, considering conditions such as magnetic field, time, strain amplitude, frequency, and temperature, and the results were compared. The results indicate that sepiolite limits the field dependent normal force of the magnetorheological grease under steady state shear, and is unaffected by magnetic field, time, temperature, and shear rate. Sepiolite has minimal impact on the transient response of the magnetorheological grease. Under oscillatory shear, the magnetic field is an important factor influencing the field-dependent normal force response of the sepiolite-magnetorheological grease (ALCH). At low magnetic fields, the field-dependent normal force of the sepiolite-containing sample (ALCH) is greater than that of the base sample (ALC), while this relationship is reversed at high magnetic fields, unaffected by other factors. Under long-term shear conditions, both samples exhibit good shear stability, as well as consistency at different frequencies and strain amplitudes. However, an increase in shear rate reduces the normal force, and temperature also affects the field-dependent normal force. The patterns of variation in steady-state and oscillatory shear modes are not entirely the same, but both exhibit a characteristic decrease with increasing temperature under high magnetic field intensities. Sepiolite can reduce the temperature sensitivity of the normal force of the magnetorheological grease. In conclusion, the introduction of sepiolite is beneficial for the application of magnetorheology in high-precision devices.

Detection of Alpha Fetoprotein Based on AIEgen Nanosphere Labeled Aptamer Combined with Sandwich Structure of Magnetic Gold Nanocomposites.

As a biomarker, alpha-fetoprotein (AFP) is valuable for detecting some tumors in men, non-pregnant women, and children. However, the detection sensitivity in some methods needs to be improved. Therefore, developing a simple, reliable, and sensitive detection method for AFP is important for non-malignant diseases. An aptamer binding was developed based on aggregation-induced emission luminogen (AIEgen) nanosphere labeled with Fe3O4@MPTMS@AuNPs. AFP was detected with a sandwich structure of AuNPs magnetic composite particles. An aggregation-induced emission (AIE) molecule and polystyrene (PS) nanosphere complex were assembled, enhancing the fluorescence and improving the sensitivity of detection. The limit of detection (LOD) was at a given level of 1.429 pg/mL, which can best be achieved in serum samples. Finally, the results obtained showed the complex to be promising in practical applications.

Modified conjoint fascial sheath suspension for the correction of severe congenital blepharoptosis in pediatric patients at different ages.

Objective: To evaluate the surgical outcomes of modified combined fascia sheath (CFS) and levator muscle (LM) complex suspension for the correction of severe congenital blepharoptosis in pediatric patients. Methods: Pediatric patients with severe congenital blepharoptosis were enrolled form July 2017 to July 2021. All patients were divided into two groups according to their age (group A ≤ 7 years; group B > 7 years) and received CFS + LM suspension surgery. Main surgical outcome indexes include margin reflex distance 1 (MRD1) and MRD1 regression. Postoperative complications such as lagophthalmos (LAG), conjunctival prolapse, exposure keratopathy and trichiasis were documented. Results: Fifty patients (60 eyes) were enrolled, including 17 patients (18 eyes) in group A and 33 patients (42 eyes) in group B. The MRD1 in group A was 3.06 ± 0.64 mm at 6 months after the operation, and the MRD1 in group B was 2.64 ± 0.69 mm 6 months postoperatively which is significantly lower than that of group A (P = 0. 044). At the last visit, however, the MRD1 in group A was 3.00 ± 0.69 mm and the MRD1 in group B was 2.64 ± 0.70 mm. There was no significant difference in MRD1 between two groups in long term (P = 0.255). Additionally, there were a variety of degrees of MRD1 regression, especially in the first month after the operation in both groups (both P < 0.001). Moreover, there were 9 cases of postoperative complications in group A and 13 cases in group B. The overall occurrence of postoperative complications in group A was significantly lower than that in groups B (χ 2 = 4.413, P = 0.036). Conclusions: CFS + LM suspension, a modified CFS-based surgery, is an effective treatment for severe congenital blepharoptosis in pediatric patients. Moreover, CFS + LM suspension demonstrate excellent long-term outcomes, including good movement of the eyelid, satisfied eyelid closure and fewer postoperative complications.

Detection of Alpha-Fetoprotein Using Aptamer-Based Sensors.

Alpha-fetoprotein (AFP) is widely-known as the most commonly used protein biomarker for liver cancer diagnosis at the early stage. Therefore, developing the highly sensitive and reliable method of AFP detection is of essential demand for practical applications. Herein, two types of aptamer-based AFP detection methods, i.e., optical and electrochemical biosensors, are reviewed in detail. The optical biosensors include Raman spectroscopy, dual-polarization interferometry, resonance light-scattering, fluorescence, and chemiluminescence. The electrochemical biosensors include cyclic voltammetry, electrochemical impedance spectroscopy, and giant magnetic impedance. Looking into the future, methods for AFP detection that are high sensitivity, long-term stability, low cost, and operation convenience will continue to be developed.

Research on the expression of elastin in the conjoint fascial sheath for the correction of severe unilateral congenital blepharoptosis.

BACKGROUND: To investigate the expression of elastin in the conjoint facial sheath (CFS) in patients with severe unilateral congenital blepharoptosis in different age groups. METHODS: Twenty-seven cases of severe unilateral congenital blepharoptosis (27 eyes) were treated with CFS + LM complex suspension from January 2020 to July 2020. Within that sample, 9 patients were over 18 years old, 9 patients were 13 to 17 years old and 9 patients were 5 to 12 years old. CFS and LM specimens were collected during CFS + LM complex suspension surgery. In the CFS specimens, the elastic fibers were observed by Victoria Blue staining. The elastin expression levels of the three groups of specimens were determined and analyzed by immunofluorescent staining and Western blotting. RESULTS: Victoria Blue staining showed that elastic fibers were abundant in CFS tissue. Moreover, immunofluorescent staining showed strong positive expression of elastin in the CFS and LM. Furthermore, in the child group, the Western blot results demonstrated that the expression of elastin was higher in the CFS than in the LM (P < 0.05). Additionally, the expression of elastin was significantly higher in the CFS of children than in that of adults or adolescents (P < 0.001). CONCLUSIONS: The CFS and LM are rich in elastic fibers and elastin, although elastin expression in the CFS decreases with age. Thus, it is feasible to apply CFS + LM complex suspension to cure severe unilateral congenital blepharoptosis.

Changes of Ocular Surface Before and After Treatment of Blepharoptosis With Combined Fascial Sheath Suspension and Frontal Muscle Flap Suspension.

OBJECTIVE: To explore the ocular surface changes after ptosis surgery in patients with severe congenital blepharoptosis. METHODS: The patients were divided into group A and group B, Group A received conjoint fascial sheath suspension, and group B received frontal muscle flap suspension. The ocular surface changes were followed upon the 7th day and in the 1st and 3rd month after operation, which included Schirmer test (ST), break-up time (BUT), tear meniscus height (TMH). For normal distribution variables, t test was used before and after operation, and the Wilcoxon test was used for variables with abnormal distribution. RESULTS: Compared to preoperative status, the ST and TMH were not significantly changed after surgery (P > 0.05), but BUT higher on the 7th day and in the 1st and 3rd month after operation (P < 0.05). The fluorescence staining (FL) score was higher in the 3rd month than that in the 1st month (P < 0.05), but was not significantly different between the 7th and in the 1st month after operation (P > 0.05). The ST, TMH, and BUT after surgery were not significantly different between groups of A and B (P > 0.05), but the FL score lower in the 3rd month than on the 7th day and in the 1st month after operation (P < 0.05). CONCLUSIONS: The ST, BUT, and TMH were not significantly changed after surgery between groups of A and B, but the FL score was lower in group A than that in group B in early postoperative time.

Ferroptosis is involved in the development of neuropathic pain and allodynia.

Neuropathic pain (NP) is chronic, intractable, and typically not alleviated using analgesics. Ferroptosis is a new type of cell death characterized by mitochondrial damage, oxidative stress, and mitochondrial dysfunction, affecting specific types of synaptic plasticity in the spinal cord. Here, we evaluated the role of ferroptosis in NP using chronic contractile injury (CCI) in rats. The CCI and control groups were subjected to sciatic nerve ligation. The mechanical withdrawal threshold and thermal withdrawal reflex latency were used to detect changes in mechanical pain threshold and thermal pain threshold in rats, respectively. Notably, CCI caused mechanical and thermal stimulation of the injured hind paw, reduced levels of glutathione peroxidase 4 (GPX4), and increased acyl-CoA synthetase long-chain family member 4 (ACSL4). Treatment with the ferroptosis inhibitor ferrostatin-1 (10 mg/kg) 1 h after surgery upregulated GPX4 expression and downregulated ACSL4 expression, whereas the ferroptosis inducer, erastin (10 mg/kg), exerted opposite effects. Treatment with ferrostatin-1 upregulated NeuN expression and downregulated GPX4 expression, whereas erastin reversed these effects. CCI increased the number of damaged mitochondria and decreased the mean planar mitochondrial area, and treatment with erastin further exacerbated these effects. The iron ion content in the spinal cords of CCI-induced rats increased. Treatment with ferrostatin-1 decreased, whereas treatment with erastin increased iron ion content in the CCI-induced rat model. Taken together, our results showed that ferroptosis is involved in the development of NP in male rats by blocking neuron and astrocyte activation in the spinal dorsal horn.

Comparison of the efficacy and safety of subthreshold micropulse laser with photodynamic therapy for the treatment of chronic central serous chorioretinopathy: A meta-analysis.

BACKGROUND: This meta-analysis was conducted to compare the therapeutic effect and safety of subthreshold micropulse laser (SML) vs photodynamic therapy (PDT) in treatment of chronic central serous chorioretinopathy (cCSC). METHODS: PubMed, EMBASE, and the Cochrane Library were searched for all relevant studies published up to August 17, 2020. Data of interest were analyzed by STATA (version 14.0) software. RESULTS: Four randomized clinical trials (RCTs) and 5 retrospective studies with 790 eyes were included in this meta-analysis after study selection. The results showed that SML significantly improved the best-corrected visual acuity (BCVA) compared with PDT at 6 to 8 weeks, 6 months, and 7 to 8 months in patients with cCSC (weighted mean difference (WMD) = -0.15, 95% confidence intervals (CI): -0.23 to -0.07, P < .01; WMD = -2.83, 95% CI: -4.79 to -0.87, P < .01; and WMD = -2.61, 95% CI: -4.23 to -1.24, P = .026, respectively). There was also a statistically significant difference between SML and PDT groups in the differences in the complete resolution of subretinal fluid (SRF) (risk radios = 0.388, 95% CI: 0.307 to 0.491, P < .01). There were no significant differences between the SML and PDT in the overall effect with central macular thickness (CMT), adverse events, complete resolution of SRF and treatment response. CONCLUSIONS: Based on the available evidence, this meta-analysis demonstrated that SML may be considered as a competitive alternative to PDT for treating cCSC, and as the first-line treatment of cCSC.

Hydrogen gas alleviates sepsis-induced neuroinflammation and cognitive impairment through regulation of DNMT1 and DNMT3a-mediated BDNF promoter IV methylation in mice.

Sepsis-associated encephalopathy (SAE) can cause acute and long-term cognitive impairment and increase the mortality rate in sepsis patients, and we previously reported that 2% hydrogen gas (H2) inhalation has a therapeutic effect on SAE, but the underlying mechanism remains unclear. Dynamic DNA methylation, which catalyzed by DNA methyltransferases (DNMTs), is involved in the formation of synaptic plasticity and cognitive memory in the central nervous system. And brain-derived neurotrophic factor (BDNF), to be a key signaling component in activity-dependent synaptic plasticity, can be induced by neuronal activity accompanied by hypomethylation of its promoter IV. This study was designed to illustrate whether H2 can mediate SAE by alter the BDNF promoter IV methylation mediated by DNMTs. We established an SAE model by cecal ligation and perforation (CLP) in C57BL/6 mice. The Morris water maze test from the 4th to the 10th day after sham or CLP operations were used to evaluate mouse cognitive function. Hippocampal tissues were isolated at the 24 after sham or CLP surgery. Pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6) and High Mobility Group Box 1 (HMGB1) were measured by enzyme-linked immunosorbent assay (ELISA). mRNA or protein levels of DNMTs (DNMT1, DNMT3a and DNMT3b), BDNF promoter IV and total BDNF were detected by RT-PCR and Western blot tests. Immunofluorescence staining were used to determine the expressions of DNMT1 and DNMT3a. The quantitative methylation analysis of the 11 CpG island of the promoter region of BDNF exon IV was determined using theAgena's MassARRAY EpiTYPER system. We found that 2% H2 inhalation can reduce pro-inflammatory factors, alleviate DNMT1, DNMT3a but not DNMT3b expression, make hypomethylation of BDNF promoter IV at 5 CpG sites, enhance the BDNF levels and then decrease escape latency but increase platform crossing times in septic mice. Our results suggest that 2% H2 inhalation may alleviate SAE through altering the regulation of BDNF promoter IV methylation which mediated by DNMT1 and DNMT3a in the hippocampus of septic mice.

FTX contributes to cell proliferation and migration in lung adenocarcinoma via targeting miR-335-5p/NUCB2 axis.

BACKGROUND: Extensive studies revealed that long non-coding RNAs (lncRNAs) could act as a regulator in tumors, including lung adenocarcinoma (LUAD). LncRNA FTX transcript, XIST regulator (FTX) has been reported to regulate the biological behaviors of some cancers. Nevertheless, its functional role and molecular mechanism remain obscure in LUAD. Our current study concentrates on exploring the biological function of FTX in LUAD. METHODS: RT-qPCR was used to test the expression of FTX, miR-335-5p or NUCB2 in LUAD cells. The effect of FTX on LUAD progression was investigated by colony formation, EdU, flow cytometry, TUNEL, transwell and western blot assays. The interaction between microRNA-335-5p (miR-335-5p) and FTX or nucleobindin 2 (NUCB2) was confirmed by luciferase reporter assay. RESULTS: RT-qPCR showed that FTX expression was up-regulated in LUAD cell lines. Loss-of-function assay indicated that FTX accelerated cell proliferation, migration and invasion, while inhibited cell apoptosis in LUAD. Besides, miR-335-5p, lowly expressed in LUAD cells, was discovered to be sponged by FTX. Subsequently, NUCB2 was identified as a target gene of miR-335-5p. Additionally, it was confirmed that NUCB2 functioned as an oncogene in LUAD. Rescue assays indicated that LUAD progression inhibited by FTX knockdown could be restored by NUCB2 up-regulation. CONCLUSION: FTX played an oncogenic role in LUAD and contributed to cancer development via targeting miR-335-5p/NUCB2 axis.

Cocaine detection using aptamer and molybdenum disulfide-gold nanoparticle-based sensors.

Aim: The current work highlighted a novel colorimetric sensor based on aptamer and molybdenum disulfide (MoS2)-gold nanoparticles (AuNPs) that was developed for cocaine detection with high sensitivity. Materials & methods: Due to the presence of the plasmon resonance band on the surface of AuNPs, AuNPs aggregated and the color was changed from red to blue after adding a certain concentration of NaCl. We used MoS2 to optimize the sensing system of AuNPs. The folded conformation of the aptamer in combination with cocaine enhanced the salt tolerance of the MoS2-AuNPs, effectively preventing their aggregation. Results & conclusion: The detection limit of cocaine was 7.49 nM with good selectivity. The method based on MoS2-AuNPs colorimetry sensor is simple, quick, label-free and low cost.

Magneto-induced rheological properties of magnetorheological gel under quasi-static shear with large deformation.

Magnetorheological gel (MRG) is a kind of magneto-sensitive smart material mainly composed of soft magnetic particles and polyurethane, which can decrease or even avoid the severe sedimentation problem appearing in MR fluids. In this work, the rheological properties of MRG under quasi-statically monotonic and cyclic loading with large deformation were investigated, respectively. The results could provide effective guidance for the design of MR devices that are often subjected to quasi-static loading. Firstly, MRG was fabricated by mixing carbonyl iron particles (CIPs) with the polyurethane matrix. Then, variations of normal force with time and magnetic field for MRG were tested and discussed. Moreover, the influences of CIPs content, shear rate, shear strain amplitude and magnetic field on the energy dissipation density of MRG were analyzed. The results showed the magneto-induced damping performance of MRG is highly relevant to the CIPs content and magnetic field, i.e. the magneto-induced enhancement of energy dissipation density of MRG with 60% CIPs content could reach up to 104 900% when the external magnetic strength increases to 391 kA m-1. Furthermore, the related mechanisms, from the perspective of microstructure, were proposed to qualitatively explain the various mechanical phenomena occurring in shear stress and normal force.

Quasi-Static Rheological Properties of Lithium-Based Magnetorheological Grease under Large Deformation.

This paper investigates the quasi-static rheological properties of lithium-based magnetorheological (MR) grease under large deformation. Three types of lithium-based MR grease comprising different mass ratios of carbonyl iron (CI) particles and lithium-based grease were prepared. The dependence of the magneto-induced stress-strain curves for MR grease on CI particles content, shear rate, and shear deformation under quasi-static monotonic shear conditions were tested and discussed. The results demonstrate that the shear rate dependence of the maximum yield stress is significantly weakened by the magnetic field, and this weakening is further enhanced as the CI particles content of MR grease increases. In addition, to evaluate and characterize the behavior of the cyclic shear-stress curves of MR grease under quasi-static condition, cyclic shear tests under different controlled conditions, i.e., CI particles content, shear rate, shear strain amplitude, and magnetic field strength, were conduct and analyzed. The magneto-induced shear stress of MR grease with higher CI particles content shows a sharp decrease during the transition from loading to unloading. Moreover, the experiment results also show that the damping characteristics of MR grease are highly correlated with CI particles content, shear strain, and magnetic field strength.

Dynamic rheological properties of polyurethane-based magnetorheological gels studied using oscillation shear tests.

This paper studies the dynamic rheological behaviors of magnetorheological (MR) gels containing different CIP weight fractions suspended in polyurethane (PU). The dynamic characteristics of prepared MR gels are obtained using large amplitude oscillation shearing (LAOS). The influence of strain amplitude, applied coil current, CIP weight fraction and driving angular frequency on the dynamic rheological properties of MR gels are systematic discussed. The results demonstrate the onset strain from linear viscoelastic region to non-linear viscoelastic region increases with applied coil current. The maximum loss modulus increases with applied coil current and CIP mass fraction. The larger the coil current and CIP mass fraction, the greater the shear strain corresponding to the maximum value. Microstructural variation of self-assembled copolymer chains and magnetic-induced CIP chains at different strain amplitudes, applied coil currents and CIP weight fractions are proposed as an explanation of the non-linear rheological behaviors of PU-based MR gels.

Normal force of lithium-based magnetorheological grease under quasi-static shear with large deformation.

An experimental study was conducted to explore the normal force of lithium-based magnetorheological (MR) grease under quasi-static shear. Firstly, MR grease with various carbonyl iron (CI) particles content was prepared. Then the influence of magnetic field strength, CI particles content, shear rate and temperature on the normal force-strain curves for MR grease under a quasi-static monotonic shear condition were investigated. The results exhibit that the normal force of MR grease under quasi-static monotonic shear decreases first and then maintains constant along with the increase of shear strain, and the critical strain is affected by the magnetic field strength and CI particles content. Finally, the normal force versus shear strain curves under different magnetic fields and shear strains were obtained by using quasi-static cyclic shear. It was found that the normal force of MRG-70 under quasi-static monotonic shear exhibits peak phenomenon at the beginning of the unloading stage, and the peak value increases with the enlargement of shear strain. Furthermore, when the strain amplitude is higher than 40%, normal force exhibits an abrupt change during the transition from the loading stage to the unloading stage.

Effect of autophagy on allodynia, hyperalgesia and astrocyte activation in a rat model of neuropathic pain.

Primary damage or dysfunction of the nervous system may cause or initiate neuropathic pain. However, it has been difficult to establish an effective treatment for neuropathic pain, as the mechanisms responsible for its pathology remain largely unknown. Autophagy is closely associated with the pathological process of neurodegenerative diseases, neuropathic injury and cancer, among others. The aim of the present study was to examine the changes in the autophagy­lysosomal pathway and discuss the effects of autophagy on allodynia, hyperalgesia and astrocyte activation in neuropathic pain. A neuropathic pain model was induced by chronic constriction injury (CCI) in rats. Inducers and inhibitors of autophagy and lysosomes were used to assess autophagy, allodynia, hyperalgesia and astrocyte activity. Neuropathic pain was found to induce an increase in the levels of the autophagy­related proteins, LC3II and Beclin 1 and, and in those of the lysosomal proteins, lysosomal­associated membrane protein type 2 (LAMP2) and Ras­related protein Rab­7a (RAB7), whereas p62 levels were found to decrease from day 1 to 14 following CCI. The autophagy inducer, rapamycin, further increased the LC3II, Beclin 1, lysosomal­associated membrane protein 2 (LAMP2) and Ras­related protein Rab­7a (RAB7) expression levels, and decreased the p62 expression levels, which were accompanied by alleviation of allodynia, hyperalgesia and astrocyte activation in the rats subjected to CCI; the autophagy inhibitor, 3­methyladenine, reversed these effects. The use of the lysosomal inhibitors, bafilomycin and chloroquine, resulted in the accumulation of LC3II and Beclin 1, a decrease in the levels of LAMP2 and RAB7, and the exacerbation of allodynia, hyperalgesia and astrocyte activation in rats with neuropathic pain. On the whole, the findings of this study indicate that neuropathic pain activates autophagy, which alleviates mechanical and thermal hyperalgesia and suppresses astrocyte activity. Therefore, neuropathic pain induced by CCI in rats appears to be mediated via the autophagy­lysosomal pathway.

Hydrogen-Rich Saline Activated Autophagy via HIF-1α Pathways in Neuropathic Pain Model.

BACKGROUND: Neuropathic pain is a chronic and intractable pain, with very few effective analgesics. It involves an impaired cell autophagy process. Hydrogen-rich saline (HRS) reportedly reduces allodynia and hyperalgesia in a neuropathic pain model; however, it is unknown whether these effects involve autophagy induction. METHODS: We investigated the relationship between HRS and cell autophagy in a neuropathic pain model generated by chronic constriction injury (CCI) in Sprague-Dawley rats. Rats received an intraperitoneal injection of HRS (10 mL/kg daily, from 1 day before until 14 days after CCI), 3MA (autophagy inhibitor), 2ME2 (HIF-1α inhibitor), or EDHB (HIF-1α agonist). The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were tested 1 day before and 1, 3, 7, 10, and 14 days after the operation. HIF-1α and cell autophagy markers in the spinal cord were evaluated by western blotting and real-time PCR assays at 14 days after CCI. Autophagosomes with double membranes were identified by transmission electron microscopy. RESULTS: CCI caused behavioral hypersensitivity to mechanical and thermal stimulation in the hind-paw of the injured side. HRS improved MWT and TWL, activated autophagy, and increased autophagosomes and autolysosomes in CCI rats. 3-MA aggravated hyperalgesia and allodynia and suppressed autophagy, while EDHB attenuated hyperalgesia and activated the autophagy procedure and the HIF-1α downstream target gene BNIP3. HIF-1α inhibitors reversed the regulatory effects of HRS on autophagy in CCI rats at 14 days after spinal cord injury. CONCLUSION: HRS reduced mechanical hyperalgesia and activation of cell autophagy in neuropathic pain through a HIF1-dependent pathway.