Gelatin methacryloyl hydrogel scaffold loaded with activated Schwann cells attenuates apoptosis and promotes functional recovery following spinal cord injury.

Spinal cord injury (SCI) is a refractory disease of the central nervous system with a high disability and incidence rate. In recent years, bioactive material combined with cell transplantation has been considered an effective method for the treatment of SCI. The present study encapsulated activated Schwann cells (ASCs) in a 3D gelatin methacryloyl (GelMA) hydrogel in order to investigate its therapeutic effects on SCI. ASCs were isolated from previously ligated rat sciatic nerves. Scanning electron microscopy and live/dead staining were used to evaluate the biocompatibility of hydrogels with the ASCs. The scaffold was transplanted into the spinal cord of rats in the hemisection model. Behavioral tests and hematoxylin and eosin staining were employed to assess the locomotion recovery and lesion areas before and after treatment. Cell apoptosis was evaluated using TUNEL staining and immunochemistry, and apoptosis-related protein expression was detected using western blot analysis. The ASCs exhibited a favorable survival and proliferative ability in the 3D GelMA hydrogel. The scaffold transplantation significantly reduced the cavities and improved functional recovery. Moreover, the GelMA/ASCs implants significantly inhibited cell apoptosis following SCI and this effect may be mediated via the p38 MAPK pathway. Overall, these findings indicated that ASCs combined with the 3D GelMA hydrogel may be a promising therapeutic strategy for SCI.

Pneumatic Retinopexy Involving the Use of Intravitreal Air Injection and Laser Photocoagulation for Rhegmatogenous Retinal Detachment in Phakic Eyes.

The clinical efficacy of pneumatic retinopexy (PR) using intravitreal pure air injection and laser photocoagulation for rhegmatogenous retinal detachment (RRD) remains unknown. Thirty-nine consecutive patients with RRD (39 eyes) were included in this prospective case series. All patients underwent two-step PR surgery containing pure air intravitreal injection and laser photocoagulation retinopexy during hospitalization. The main outcomes were best-corrected visual acuity (BCVA) and primary anatomic success rates after PR treatment. The mean follow-up was 18.3 ± 9.7 months, ranging from 6 to 37 months. The primary anatomic success rate was 89.7% (35/39) after PR treatment. Final reattachment of the retina was achieved in 100% of cases. Macular epiretinal membrane was developed in two patients (5.7%) among successful PR cases during the follow-up. The mean logMAR BCVA value was significantly improved from 0.94 ± 0.69 before surgery to 0.39 ± 0.41 after surgery. The average central retinal thickness was significantly thinner in the RRD eyes of macula-off patients (206.8 ± 56.13 µm) when compared with the fellow eyes (234.6 ± 48.4 µm) at the last follow-up (p = 0.005). This study concluded that an inpatient PR procedure with pure air injection and laser photocoagulation is a safe and effective approach to treating patients with RRD, who may achieve a high single-operation success rate and good visual acuity recovery.

Cerium Oxide Nanoparticles Alleviate Neuropathic Pain by Modulating Macrophage Polarization in a Rat SCI Model.

Context: Chronic neuropathic pain (NP) frequently occurs after spinal cord injury (SCI) but lacks effective therapeutic options in the clinic. Numerous evidence indicates the involvement of macrophages activation in the NP, and the modulation of macrophages is promising for NP treatment. In this study, we introduce Cerium oxide nanoparticles (CONPs) and aim to investigate whether it can relieve the NP by modulating macrophage polarization. Methods: CONPs were prepared using the hydrothermal method. In vitro, different concentrations of CONPs were used to cultivate macrophages (RAW 264.7). In vivo, the analgesic effect of CONPs was investigated in a contusive rat SCI model. Mechanical paw withdrawal threshold (PWT) and thermal paw withdrawal latency (PWL) were tested to evaluate pain behaviors. Immunofluorescence staining and real-time quantitative polymerase chain reaction were applied to assess macrophage phenotypes. Results: The synthesized CONPs were 6.8 ± 0.5 nm in size, presenting a cubic morphology. Live/dead staining showed that the relatively low concentrations of CONPs (less than 800 µg/mL) displayed good biocompatibility with macrophages. Intrathecal injection of CONPs could significantly increase the mechanical PWT and thermal PWL of SCI rats. Molecular experiments results showed the expression of M2 macrophage-related markers (CD206, Arg-1, IL-10) were significantly increased, while that of M1 macrophage-related markers (CD86, TNF-α, iNOS) were downregulated after CONPs treatment. Conclusion: Our study suggests that CONPs can relive the NP following SCI by promoting M2 macrophages polarization, which provides a novel insight for the treatment of SCI induced NP.

Circular RNA Hecw1 Regulates the Inflammatory Imbalance in Spinal Cord Injury via miR-3551-3p/LRRTM1 Axis.

Spinal cord injury (SCI) is a neurological disease having devastating effect and results in the development of systemic inflammation. However, the molecular mechanisms of SCI remain not entirely elucidated. This study was directed toward exploring the circ Hecw1 involved in the mechanism of lipopolysaccharide (LPS)-triggered inflammation damage in neuronal cells. The in vitro model of SCI based on PC12 cells were established with lipopolysaccharide. The cell proliferation was determined by the use of cell counting kit-8 (CCK8). The expressions of circHecw1, miR-3551-3p, and inflammatory factors were measured by quantitative real-time PCR and ELISA assay. Flow cytometry was used to assess apoptosis. Western blot analysis was performed for the purpose of determining LRRTM1 and NF-kB signaling. The expression of circ Hecw1, TNF-α, IL-6, and IL-1ß in LPS-triggered PC12 cells and the expression of miR-3551-3p and IL-10 were significantly decreased. Knockdown of circHecw1 promoted proliferation and inhibited apoptosis and reduction in the inflammatory cytokine expression. Our study revealed that circHecw1 regulates SCI neuronal cell inflammation imbalance by regulating the miR-3551-3p/LRRTM1 signaling.

Autophagy Protects Ocular Surface Against Overactivated Inflammation by Degrading Retinoic Acid-Induced Gene-I in Human Conjunctival Epithelial Cells.

Purpose: To evaluate the pathological role of autophagy in dry eye diseases by detecting the autophagic degradation of RIG-I, a master RNA-sensing receptor in cells. Methods: RNA-sequencing analysis and qPCR analysis of the expression level of genes related to IFN-I signaling pathway was used to evaluate the inflammatory level of cells overexpressed with RIG-I or empty vector, which was further confirmed by WB analysis. Chemical treatment (3-methyladenine, chloroquine, NH4Cl, rapamycin, torin 1 or trehalose) or gene knockdown was used to modulate autophagy. When the autophagy level was regulated, the autophagic degradation of RIG-I and its pathological role in dry eye diseases were determined by detecting the protein level of RIG-I and the level of cell inflammation. Results: Cells that overexpressed RIG-I showed increased expression of genes involved in the IFN-I signaling pathway compared with cells transfected with an empty vector. Inhibition of autophagy leaded to the accumulation of RIG-I in HCECs, combined with the aggravation of the RIG-I-mediated IFN-I signaling pathway. Contrarily, promoting the autophagic degradation of RIG-I by trehalose treatment could alleviate IFN-I signaling pathway. Conclusions: Autophagy could protect the ocular surface against IFN-I signaling pathway by degrading RIG-I in HCECs. This process may restrict the overactivation of inflammation in the pathological development of dry eye disease.

TNF-like weak inducer of apoptosis / nuclear factor κB axis feedback loop promotes spinal cord injury by inducing astrocyte activation.

Non-canonical signaling pathways have been proved to act as potent sites of astrocytes osmotic expanding or proliferation, which promotes the regeneration of axons in areas with non-neural spinal cord injury (SCI). However, the relevant signal pathway that induces autophagic cell death in astrocytes and its function relative to the TNF-like weak inducer of apoptosis/nuclear factor κB (TWEAK/NF-κB) axis remains elusive. The SCI model was established by vertically striking the spinal cord according to Allen's model. Astrocytes and neuronal cells were prepared from spinal cells extracted from spinal cord tissues of SCI or normal C57BL/6 newborn mice. After co-culturing astrocytes and neurons, cell viability and autophagy were determined by CCK-8, transmission electron microscopy (TEM), and western blot. The expression of TWEAK, NF-κB and inflammatory cytokines was confirmed by qRT-PCR, western blot, Immunofluorescence and ELISA assay. Chromatin immunoprecipitation (CHIP) was used to evaluate the interaction between TWEAK and NF-κB. Our results demonstrated that knockdown of TWEAK and NF-κB inhibited secretion of high levels of TNF-α/IL-1ß, partially counteracted by adding Rap. TWEAK/NF-κB was the positive correlation feedback loop regulating the proliferation and autophagy of astrocytes involved in SCI. Moreover, restraining the excess growth of astrocytes was beneficial to the growth of neurons. Collectively, our findings illustrated that the TWEAK/NF-κB pathway might act as a positive modulator of SCI by inducing astrocyte activation, shedding new insights for SCI treatment.

Efficacy of carbonic anhydrase inhibitors in management of cystoid macular edema in retinitis pigmentosa: A meta-analysis.

BACKGROUND: Carbonic anhydrase inhibitors (CAI) are often used in the treatment of cystoid macular edema (CME) in retinitis pigmentosa (RP) patients. The aim of this meta-analysis is to gain a better understanding of the overall efficacy of CAI treatment. METHODS: Databases including PubMed, EMBASE, and Cochrane Library were searched to identify relevant studies. Eligible studies were clinical trials of patients with RP assigned topical or oral CAIs such as dorzolamide and acetazolamide. Changes in central macular thickness (CMT) by OCT in µm and best-corrected visual acuity (BCVA) in log MAR equivalents were extracted and results compared between baseline and after treatment. RESULTS: 11 clinical reports were identified which included a total of 194 patients (358 eyes) available for analysis, with 59 patients (115 eyes) assigned oral CAI treatment and 135 patients (243 eyes) assigned topical CAI treatment. The combined results showed a significant reduction of macular edema, as calculated by baseline and final central macular thickness (CMT) based on OCT examination (46.02µm, 95%CI: -60.96, -31.08, I2 = 65%). However, the effect on visual acuity was inconsistent across studies. CONCLUSION: Based on non randomized controlled clinical studies, RP patients with CME who were treated with CAIs had better anatomical outcomes, but the effect on visual acuity was contradictory across studies. Multicenter prospective randomized controlled trials would be ideal to definitively test its clinical efficacy in RP patients.

Effects of miRNA-200b on the development of diabetic retinopathy by targeting VEGFA gene.

The present study explored the effect of miR-200b on the development of diabetic retinopathy (DR) by targeting vascular endothelial growth factor A (VEGFA) gene. The study populations consisted of 255 DR patients (case group) and 253 healthy people (control group), while the expressions of miR-200b and VEGFA mRNA were detected by quantitative real-time PCR (qRT-PCR). Bioinformatics software and dual-luciferase reporter assay were used to confirm VEGFA as a target gene of miR-200b Also, a total of 70 Wistar male rats were selected and randomly assigned into blank, normal control (NC), miR-200b mimics, miR-200b inhibitors, miR-200b inhibitors + silencing vascular endothelial growth factor A (siVEGFA), and siVEGFA groups (n=10/group) respectively. Streptozotocin (STZ)-induced rat models of DR were successfully established. VEGFA, transforming growth factor-ß1 (TGF-ß1), hepatocyte growth factor (HGF), and pigment epithelium-derived factor (PEDF) were detected using qRT-PCR and Western blotting. In comparison with the control group, the case group showed lower expression of miR-200b but higher expression of VEGFA mRNA. VEGFA was confirmed as a target gene of miR-200b Rats in the miR-200b mimics and siVEGFA groups exhibited higher expression of PEDF mRNA and protein but lower expressions of VEGFA, TGF-ß1, HGF protein, and mRNA than the NC group. There was no remarkable difference in expressions of PEDF, VEGFA, TGF-ß1, HGF protein, and mRNA between the miR-200b inhibitors + siVEGFA and NC groups. In conclusion, the present study demonstrated that miR-200b might alleviate DR development by down-regulating its target gene VEGFA.