By Activating Akt/eNOS Bilobalide B Inhibits Autophagy and Promotes Angiogenesis Following Focal Cerebral Ischemia Reperfusion.

BACKGROUND/AIMS: Ischemic stroke is a leading cause of long-term disability. To date, there is no effective treatment for stroke. Previous studies have shown that Ginkgo biloba extract has protective effects against neurodegenerative disorders. In this present study, we sought to test the potential protective role of an active component of Ginkgo biloba extract, bilobalide, in a rat model of middle cerebral artery occlusion (MCAO). METHODS: A rat model of MCAO was used to test the potential protective effects of Bilobalide B on stroke protection. TTC staining was performed to evaluate infarct size of the brains. Neurological deficit score was measured to reveal the effects of the treatments on animal behavior and cognition. Immunohistochemical staining and transmission electronic microscope analysis were performed to measure the cellular responses to drug treatment. Western blotting and ELISA were performed. The expression of Cleaved- Casepase 3, Beclin-1, p62 and LC3I/II were quantified, and the Phosphorylation of eNOS and Akt were evaluated. The ratio of Bcl-2/ Bax was determined to reveal the molecular pathways that are involved in the drug treatment. RESULTS: We found that intraperitoneal delivery of various Bilobalide doses during ischemia can protect against brain injury, as evidenced by reduced infarct size and improved neurological scores after surgery. Histochemical analysis revealed that treatment with bilobalide can significantly reduce apoptosis, autophagy, and promote angiogeneis following ischemia/reperfusion injury to the brain. The performence of increased phosphorylation of eNOS and Akt suggested that bilobalide can activate Akt prosurvival and eNOS pathways to promote cell survival and angiogenesis, respectively. CONCLUSIONS: Our results suggested that bilobalide benefits stroke symptoms by reducing cell death pathways and promoting angiogenesis. As such, bilobalide may be a potential agent for improving self-repair after ischemic stroke.

Overexpression of Long Non-Coding RNA ZXF2 Promotes Lung Adenocarcinoma Progression Through c-Myc Pathway.

OBJECTIVE: To investigate the expression of long non-coding RNA ZXF2 in lung adenocarcinoma tissues and its effect on cell proliferation, migration and invasion. METHODS: Forty pairs of cancerous and adjacent non-cancerous lung adenocarcinoma specimens were collected for the studies. Quantitative real-time PCR was used to analyze the expression of ZXF2 in tumor tissues and adjacent normal tissues. The expression of ZXF2 was correlated with patients' clinico-pathological data. Molecular pathway controlled by ZXF2 was explored by using small interfering RNA (siRNA) technology. CCK-8 cell proliferation assay, flow cytometry analysis and transwell assays were used to evaluate cell proliferation, migration and invasion. RESULTS: The expression of ZXF2 was 2 fold or higher in 27 out of 40 (67.5%) cases of lung adenocarcinoma specimens than that in non-cancerous tissues (P<0.05). The relative expression level of ZXF2 was positively correlated with tumor lymph node metastasis (χ(2)=8.485, P<0.05) and poor prognosis of the patients (p=0.0217). In order to explore the molecular mechanisms of ZXF2 mediated tumor progression, ZXF2 expression was inhibited by siRNA in A549 cells, a highly aggressive and metastatic lung adenocarcinoma cell line. We found that siRNA-ZXF2 treatment inhibited cell proliferation (P<0.01) leading to cell cycle arrest (P<0.01). The cell migration and invasion were suppressed by siRNA-ZXF2 treatment (P<0.01). Further biochemical studies revealed that the knockdown of ZXF2 led to down regulation of c-Myc signaling. CONCLUSION: ZXF2 was overexpressed in lung adenocarcinoma tissues and the high expression of ZXF was closely related to tumor progression through c-Myc related pathway. Given the fact that both ZXF2 and c-Myc are located in the same chromosome 8q24.2 loci, the potential interaction between ZXF2 and c-Myc might be a novel target for treatment of lung adenocarcinoma.

Urinary Trypsin Inhibitor Attenuates Acute Lung Injury by Improving Endothelial Progenitor Cells Functions.

BACKGROUND: Urinary Trypsin Inhibitor (UTI) is involved in various aspects of tissue repair, regeneration and development. However, the potential role of UTI in protection against acute lung injury (ALI) remains largely unknown. In the present study, we demonstrated that UTI treatment could ameliorate ALI induced by oleic acid (OA) treatment in rabbit model. METHODS: Intravenous application of UTI (10000 U/kg/d) significantly improved the pathologies associated with OA-induced ALI. The lungs were stained with hematoxylin and eosin to scored the lung injury. Peripheral blood mononuclear cells were isolated by density gradient centrifugation with Ficoll-Plaque Plus. The proliferation and ability of tube structure formation of EPCs were observed and the level of phosphorylated Akt protein expression and eNOS protein expression were assayed. RESULTS: Consistent with pathological scores, UTI treatment significantly reduced wet/dry ratio of OA injured lungs. A quantification of capillary density revealed that UTI treatment led to about 2 fold increase over uninjured control and about 1.5 fold increase over PBS treatment. The capacity for tube formation of EPCs on ECM gel was significantly reduced in the ALI group and recovered with UTI treatment. Quantification of western blot bands was summarized and showed that UTI treatment activates Akt/eNOS signaling. NO production could contribute to the improvement of EPCs function by UTI treatment. CONCLUSIONS: UTI-induced phosphorylation/activation of eNOS and Akt, increases the intracellular level of NO, thereby improving tube formation and proliferation function of EPCs. EPCs function is crucial for re-endothelialization after denuding injuries of arteries.

Ex vivo analysis of ketotifen content in an antihistamine-eluting contact lens worn up to 5 hours.

Aim: This study characterized ex vivo release of ketotifen from etafilcon A contact lenses worn over 5 h. Materials & methods: 14 participants, 21 to 59 years, wore lenses with 19 µg ketotifen over 8 visits, for 1 min to 5 h. Residual ketotifen was measured using high-performance liquid chromatography (HPLC) compared with unworn lenses from the same lots to determine percent ketotifen remaining. Results: Residual ketotifen ranged from 16.19 µg ± 0.44 (84.1%) [1 minute] to 0.20 µg ± 0.07 (1.1%) [5 h]. No adverse events or clinically significant biomicroscopy changes were observed. Conclusion: The ketotifen-releasing etafilcon A lenses were well-tolerated with an acceptable safety profile in the population studied. The release of ketotifen from study lenses over 5 h was consistent with a diffusion-controlled system.

This article is about measuring how fast a medication to relieve itchy eyes from allergies is released from contact lenses that are worn for a single day and then discarded. The study showed that the medication is initially released rapidly over the first 15 min of wear and then more slowly over the next 4+ h until almost none remains. This means that people who have itchy eyes from allergies may be able receive their medication by just wearing these contact lenses each day during their allergy season, without having to put in extra eye drops.

MG53 Inhibits Necroptosis Through Ubiquitination-Dependent RIPK1 Degradation for Cardiac Protection Following Ischemia/Reperfusion Injury.

Rationale: While reactive oxygen species (ROS) has been recognized as one of the main causes of cardiac injury following myocardial infarction, the clinical application of antioxidants has shown limited effects on protecting hearts against ischemia-reperfusion (I/R) injury. Thus, the precise role of ROS following cardiac injury remains to be fully elucidated. Objective: We investigated the role of mitsugumin 53 (MG53) in regulating necroptosis following I/R injury to the hearts and the involvement of ROS in MG53-mediated cardioprotection. Methods and Results: Antioxidants were used to test the role of ROS in MG53-mediated cardioprotection in the mouse model of I/R injury and induced human pluripotent stem cells (hiPSCs)-derived cardiomyocytes subjected to hypoxia or re-oxygenation (H/R) injury. Western blotting and co-immunoprecipitation were used to identify potential cell death pathways that MG53 was involved in. CRISPR/Cas 9-mediated genome editing and mutagenesis assays were performed to further identify specific interaction amino acids between MG53 and its ubiquitin E3 ligase substrate. We found that MG53 could protect myocardial injury via inhibiting the necroptosis pathway. Upon injury, the generation of ROS in the infarct zone of the hearts promoted interaction between MG53 and receptor-interacting protein kinase 1 (RIPK1). As an E3 ubiquitin ligase, MG53 added multiple ubiquitin chains to RIPK1 at the sites of K316, K604, and K627 for proteasome-mediated RIPK1 degradation and inhibited necroptosis. The application of N-acetyl cysteine (NAC) disrupted the interaction between MG53 and RIPK1 and abolished MG53-mediated cardioprotective effects. Conclusions: Taken together, this study provided a molecular mechanism of a potential beneficial role of ROS following acute myocardial infarction. Thus, fine-tuning ROS levels might be critical for cardioprotection.

MG53 Preserves Neuromuscular Junction Integrity and Alleviates ALS Disease Progression.

Respiratory failure from progressive respiratory muscle weakness is the most common cause of death in amyotrophic lateral sclerosis (ALS). Defects in neuromuscular junctions (NMJs) and progressive NMJ loss occur at early stages, thus stabilizing and preserving NMJs represents a potential therapeutic strategy to slow ALS disease progression. Here we demonstrate that NMJ damage is repaired by MG53, an intrinsic muscle protein involved in plasma membrane repair. Compromised diaphragm muscle membrane repair and NMJ integrity are early pathological events in ALS. Diaphragm muscles from ALS mouse models show increased susceptibility to injury and intracellular MG53 aggregation, which is also a hallmark of human muscle samples from ALS patients. We show that systemic administration of recombinant human MG53 protein in ALS mice protects against injury to diaphragm muscle, preserves NMJ integrity, and slows ALS disease progression. As MG53 is present in circulation in rodents and humans under physiological conditions, our findings provide proof-of-concept data supporting MG53 as a potentially safe and effective therapy to mitigate ALS progression.

Recombinant Human MG53 Protein Protects Against Alkaline-Induced Corneal Injuries in Mice.

INTRODUCTION: The current study was designed to test the potential role of recombinant human MG53 (rhMG53) protein on protecting against alkaline-induced corneal injury in mice. MATERIALS AND METHODS: A round filter paper with 2-mm diameter was soaked in 1 mol/L of NaOH solution. The mouse alkaline injury was generated by placing the filter paper directly on the cornea for 30 seconds and washed with 30-mL saline; 10 µL of rhMG53 solution (20 µg/mL) or saline control was topically administrated on the mouse corneas (twice per day for 10 days). Re-epithelialization was measured by fluorescein staining and imaged by a slit lamp equipped with a digital camera. Clinical neovascularization and opacity scores were measured every day after injury. Ten days after injury, mice were sacrificed and corneas were dissected out for flat mount staining of CD31 for neovascularization. RESULTS: MG53 was present in both dog aqueous humor and human tears. mg53-/- corneas were more susceptible to alkaline-induced corneal injury. Topical treatment of rhMG53 improved re-epithelialization, suppressed neovascularization, and fibrosis induced by alkaline injury. CONCLUSIONS: rhMG53 may be an effective means to treat corneal wounding.

Management of Ocular Allergy Itch With an Antihistamine-Releasing Contact Lens.

PURPOSE: A contact lens (CL)-based drug delivery system for therapeutic delivery of the antihistamine ketotifen was tested in 2 parallel, conjunctival allergen challenge-based trials. METHODS: Both trials employed the same multicenter, randomized, placebo-controlled protocol. Test lenses were etafilcon A with 0.019 mg ketotifen; control lenses were etafilcon A with no added drug. Subjects were randomized into 3 treatment groups. Group 1 received test lens in one eye and control lens in the contralateral eye; the eye chosen to receive test lens was randomly selected in a 1:1 ratio. Group 2 received test lenses bilaterally, and group 3 received control lenses bilaterally. Allergen challenges were conducted on 2 separate visits: following lens insertion, the subjects were challenged at 15 minutes (to test onset) and 12 hours (to test duration). The primary endpoint was ocular itching measured using a 0 to 4 scale with half-unit steps. Secondary endpoints included ciliary, conjunctival, and episcleral hyperemia. RESULTS: The mean itching scores were lower for eyes wearing the test lens as compared to those that received control lenses, indicating that the test lens effectively reduced allergic responses. Mean differences in itching were statistically and clinically significant (mean score difference ≥ 1) at both onset and duration for both trials. CONCLUSIONS: This large-scale assessment (n = 244) is the first demonstration of efficacy for CL delivery of a therapeutic for ocular allergy. Results are comparable to direct topical drug delivery and suggest that the lens/ketotifen combination can provide a means of simultaneous vision correction and treatment for CL wearers with ocular allergies.

MG53 promotes corneal wound healing and mitigates fibrotic remodeling in rodents.

The cornea plays an important role in transmitting light and providing protection to the eye, but is susceptible to injury and infection. Standard treatments for corneal wounds include topical lubricants, antibiotics, bandage contact lens, and surgery. However, these measures are often ineffective. Here we show that MG53, a protein with an essential role in cell membrane repair, contributes to the corneal injury-repair process. Native MG53 is present in the corneal epithelia, tear film, and aqueous humor, suggesting its potential function in corneal homeostasis. Knockout of MG53 in mice causes impaired healing and regenerative capacity following injury. Exogenous recombinant human MG53 (rhMG53) protein protects the corneal epithelia against mechanical injury and enhances healing by promoting migration of corneal fibroblasts. Using in vivo alkaline-induced injury to the rat cornea, we show that rhMG53 promotes re-epithelialization and reduces post-injury fibrosis and vascularization. Finally, we show that rhMG53 modulates TGF-ß-mediated fibrotic remodeling associated with corneal injury. Overall, our data support the bi-functional role of MG53 in facilitating corneal healing and maintaining corneal transparency by reducing fibrosis and vascularization associated with corneal injuries.

Sustained elevation of MG53 in the bloodstream increases tissue regenerative capacity without compromising metabolic function.

MG53 is a muscle-specific TRIM-family protein that presides over the cell membrane repair response. Here, we show that MG53 present in blood circulation acts as a myokine to facilitate tissue injury-repair and regeneration. Transgenic mice with sustained elevation of MG53 in the bloodstream (tPA-MG53) have a healthier and longer life-span when compared with littermate wild type mice. The tPA-MG53 mice show normal glucose handling and insulin signaling in skeletal muscle, and sustained elevation of MG53 in the bloodstream does not have a deleterious impact on db/db mice. More importantly, the tPA-MG53 mice display remarkable dermal wound healing capacity, enhanced muscle performance, and improved injury-repair and regeneration. Recombinant human MG53 protein protects against eccentric contraction-induced acute and chronic muscle injury in mice. Our findings highlight the myokine function of MG53 in tissue protection and present MG53 as an attractive biological reagent for regenerative medicine without interference with glucose handling in the body.

Effect of metabolic syndrome on mitsugumin 53 expression and function.

Metabolic syndrome is a cluster of risk factors, such as obesity, insulin resistance, and hyperlipidemia that increases the individual's likelihood of developing cardiovascular diseases. Patients inflicted with metabolic disorders also suffer from tissue repair defect. Mitsugumin 53 (MG53) is a protein essential to cellular membrane repair. It facilitates the nucleation of intracellular vesicles to sites of membrane disruption to create repair patches, contributing to the regenerative capacity of skeletal and cardiac muscle tissues upon injury. Since individuals suffering from metabolic syndrome possess tissue regeneration deficiency and MG53 plays a crucial role in restoring membrane integrity, we studied MG53 activity in mice models exhibiting metabolic disorders induced by a 6 month high-fat diet (HFD) feeding. Western blotting showed that MG53 expression is not altered within the skeletal and cardiac muscles of mice with metabolic syndrome. Rather, we found that MG53 levels in blood circulation were actually reduced. This data directly contradicts findings presented by Song et. al that indict MG53 as a causative factor for metabolic syndrome (Nature 494, 375-379). The diminished MG53 serum level observed may contribute to the inadequate tissue repair aptitude exhibited by diabetic patients. Furthermore, immunohistochemical analyses reveal that skeletal muscle fibers of mice with metabolic disorders experience localization of subcellular MG53 around mitochondria. This clustering may represent an adaptive response to oxidative stress resulting from HFD feeding and may implicate MG53 as a guardian to protect damaged mitochondria. Therapeutic approaches that elevate MG53 expression in serum circulation may be a novel method to treat the degenerative tissue repair function of diabetic patients.

Defective mitochondrial dynamics is an early event in skeletal muscle of an amyotrophic lateral sclerosis mouse model.

Mitochondria are dynamic organelles that constantly undergo fusion and fission to maintain their normal functionality. Impairment of mitochondrial dynamics is implicated in various neurodegenerative disorders. Amyotrophic lateral sclerosis (ALS) is an adult-onset neuromuscular degenerative disorder characterized by motor neuron death and muscle atrophy. ALS onset and progression clearly involve motor neuron degeneration but accumulating evidence suggests primary muscle pathology may also be involved. Here, we examined mitochondrial dynamics in live skeletal muscle of an ALS mouse model (G93A) harboring a superoxide dismutase mutation (SOD1(G93A)). Using confocal microscopy combined with overexpression of mitochondria-targeted photoactivatable fluorescent proteins, we discovered abnormal mitochondrial dynamics in skeletal muscle of young G93A mice before disease onset. We further demonstrated that similar abnormalities in mitochondrial dynamics were induced by overexpression of mutant SOD1(G93A) in skeletal muscle of normal mice, indicating the SOD1 mutation drives ALS-like muscle pathology in the absence of motor neuron degeneration. Mutant SOD1(G93A) forms aggregates inside muscle mitochondria and leads to fragmentation of the mitochondrial network as well as mitochondrial depolarization. Partial depolarization of mitochondrial membrane potential in normal muscle by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) caused abnormalities in mitochondrial dynamics similar to that in the SOD1(G93A) model muscle. A specific mitochondrial fission inhibitor (Mdivi-1) reversed the SOD1(G93A) action on mitochondrial dynamics, indicating SOD1(G93A) likely promotes mitochondrial fission process. Our results suggest that accumulation of mutant SOD1(G93A) inside mitochondria, depolarization of mitochondrial membrane potential and abnormal mitochondrial dynamics are causally linked and cause intrinsic muscle pathology, which occurs early in the course of ALS and may actively promote ALS progression.