N-acetyl-L-cysteine attenuated the toxicity of ZIF-8 on EA.hy926 endothelial cells by wnt/ß-catenin pathway.

As kinds of porous crystalline compounds, zeolitic imidazolate frameworks (ZIFs) have been developed quickly and attracted considerable attention for use in nano drug delivery systems, which raised concerns about cardiovascular disorders. At the present, the cytotoxic mechanism of ZIFs in cardiovascular disorders was still unclear. Our experiment explored the toxicity of ZIF-8, a typical kind of ZIFs, on human EA.hy926 vascular endothelial cells. The cell viability, ROS formation, apoptosis level, inflammatory response level, wound healing ability and atherosclerosis-related indicators of EA.hy926 endothelial cells were analyzed after ZIF-8 treatment. Meanwhile, we evaluated the ability of antioxidant N-Acetyl-L-cysteine (NAC) to attenuate the toxicity of ZIF-8 on EA.hy926 endothelial cells. As results, NAC attenuated ROS formation, cell apoptosis, LDH formation and endothelial dysfunction caused by ZIF-8. As the Wnt/ß-catenin pathway was involved in endothelial cell dysfunction, we also studied the expression level of ß-catenin and LEF1 in ZIF-8 and/or NAC treated EA.hy926 cells. As expected, ZIF-8 increased the protein expressions of ß-catenin and LEF1in the IC50 group, which was significantly inhibited by co-treatment with NAC. Taken together, this study could help improve our understanding about the mechanism of ZIF-8-induced endothelial cells injury and NAC had therapeutic potential in preventing ZIF-8-associated endothelial dysfunction by wnt/ß-catenin pathway.

A novel leptin receptor binding peptide tethered-collagen scaffold promotes lung injury repair.

Lung regeneration after acute injury usually depends on stem cell migration and differentiation, and functional alveoli-like tissue and capillary structure formation. The homing of mesenchymal stem cells (MSCs) to injury sites promotes lung repair through damaged cell replacement and anti-inflammatory and anti-fibrotic effects. Here, we aimed to improve therapeutic effects of the endogenous MSCs by increasing their homing efficiency. We have identified a high-affinity leptin receptor (LEPR)-binding peptide using a phage display screening technique, as the LEPR is highly expressed in MSCs. The selected LEPR-binding peptides were modified with a collagen binding peptide for specifically tethering to a collagen scaffold. After implantation of the LEPR-binding peptide functionalized collagen scaffold in a rat model of acute lung injury, the endogenous LEPR+ MSCs were specifically recruited out of circulation to the scaffold, and their retention periods in the damaged area were significantly prolonged. The migrated MSCs in the functional scaffold promoted the differentiation of type Ⅱ alveolar epithelial cells to type Ⅰ alveolar epithelial cells and facilitated alveoli-like tissue and capillary formation, thus improved lung function recovery. These results suggest that tethering the LEPR binding peptides to the collagen scaffold significantly enhanced endogenous MSC recruitment and promoted functional regeneration of injured lung tissue.

Clinical benefit of tunnel endoscopic submucosal dissection for esophageal squamous cancer: a multicenter, randomized controlled trial.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) is widely accepted as a primary treatment modality for dysplastic and early cancerous lesions of the GI tract. However, prolonged procedure time and life-threatening adverse events remain obstacles to the successful treatment of esophageal cancer. This study aimed to compare the efficacy and safety of tunnel ESD (T-ESD) with conventional ESD (C-ESD) for superficial esophageal squamous neoplasms. METHODS: A prospective, multicenter trial was conducted at 5 hospitals in China. Patients with esophageal squamous neoplasms were enrolled and randomly assigned to undergo C-ESD or T-ESD. Randomization was stratified by tumor location and circumference extent (<1/2 or ≥1/2). The primary endpoint was procedure time. RESULTS: Between January and July 2018, 160 patients were enrolled. One hundred fifty-two patients (76 in the C-ESD group and 76 in the T-ESD group) were included in the final analysis. The median procedure time was 47.3 minutes (interquartile range, 31.7-81.3) for C-ESD and 40.0 minutes (interquartile range, 30.0-60.0) for T-ESD (P = .095). However, T-ESD specifically reduced the median procedure time 34.5% (29.5 minutes) compared with C-ESD for lesions ≥1/2 circumference (P < .001). Among the multiple secondary outcomes, muscular injury was less frequent in the T-ESD group compared with the C-ESD group (18.4% vs 38.2%, P = .007), but complete healing of artificial mucosal defect in 1-month follow-up was more common in the T-ESD group than the C-ESD group (95.9% vs 84.7%, P =.026). CONCLUSIONS: Our study suggests that T-ESD results in shorter procedure time, specifically for lesions ≥1/2 circumference of the esophagus. In addition, T-ESD has a better safety profile indicated by less frequent muscular injury and improved healing of artificial mucosal defects caused by ESD procedures. (Clinical trial registration number: NCT03404921.).

Sympathetic Nerve-Mediated Fellow Eye Pain During Sequential Cataract Surgery by Regulating Granulocyte Colony Stimulating Factor CSF3.

Patients were found to experience more pain during their second eye cataract surgery compared with their first eye surgery. This study aimed to explore the inflammatory alterations along time in the fellow eye after the first eye surgery and to reveal the underlying mechanism. Eighty patients with bilateral cataracts were recruited and were divided into four groups based on the time of having the second eye surgery. The second eye aqueous humor samples were collected just before surgery and analyzed by mass spectrometry and PCR array. Cytokine activity was enriched in the aqueous humor of the contralateral eye with granulocyte colony-stimulating factor CSF3 significantly upregulated at both gene and protein levels. Rabbits with or without superior cervical ganglionectomy (SCGx) were subjected to lensectomy to mimic human situations. In both human and rabbit models, the fellow eye CSF3 peaked at 1 week post the first eye surgery. Consistently, more neutrophils were recruited to the contralateral eye aqueous humor. Corneal sensitivity and trigeminal electrophysiology were recorded to imply the pain severity in rats receiving capsulorrhexis with or without SCGx. A more intense pulse was detected in the contralateral trigeminal ganglion after the rat received one eye surgery. SCGx could effectively reduce the fellow corneal sensitivity and trigeminal nerve pain. These alterations were under direct regulation of the sympathetic nerves on the surgical eye side. Our results suggest that CSF3 and sympathetic activity could serve as potential analgesic targets during ocular surgeries.

The Adaptive Responses in Non-Small Cell Lung Cancer A549 Cell Lines Induced by Low-Dose Ionizing Radiation and the Variations of miRNA Expression.

OBJECTIVE: To study the effects of adaptive response in A549 cells induced by low-dose radiation and the miRNAs expression. METHODS: A549 cells were irradiated with 50 mGy and 200 mGy initial doses, respectively, and then irradiated with a challenge dose 20 Gy at 6 hours interval. The biological effects and miRNA expression were detected. RESULTS: The apoptosis rates of 50 mGy-20 Gy and 200 mGy-20 Gy groups were significantly lower than that of only 20 Gy irradiation group (P < .05). The percentage of G2/M phase cells of 50 mGy-20 Gy and 200 mGy-20 Gy groups was significantly decreased relative to the 20 Gy group (P < .05). One miRNA (mir-3662) was upregulated and 15 miRNAs (mir-185, mir-1908, mir-307, mir-182, mir-92a, mir-582, mi-r501, mir138-5p, mir-1260, mir-484, mir-378d, mir-193b, mir-127-3p, mir-1303, and mir-654-5p) were downregulated both in 50 mGy-20 Gy and 200 mGy-20 Gy groups than that of the 20 Gy group. Go and KEGG enrichment analysis showed that the target genes were significantly enriched in cell communication regulation, metabolic process, enzyme binding, and catalytic activity signaling pathways. CONCLUSION: Low-dose X-ray of 50 mGy and 200 mGy radiation can induce adaptive apoptosis response prior to 20 Gy in A549 cells. Sixteen differently expressed miRNAs may play important roles in the adaptive effect of low-dose radiation.

Direct neuronal differentiation of neural stem cells for spinal cord injury repair.

Spinal cord injury (SCI) typically results in long-lasting functional deficits, largely due to primary and secondary white matter damage at the site of injury. The transplantation of neural stem cells (NSCs) has shown promise for re-establishing communications between separated regions of the spinal cord through the insertion of new neurons between the injured axons and target neurons. However, the inhibitory microenvironment that develops after SCI often causes endogenous and transplanted NSCs to differentiate into glial cells rather than neurons. Functional biomaterials have been shown to mitigate the effects of the adverse SCI microenvironment and promote the neuronal differentiation of NSCs. A clear understanding of the mechanisms of neuronal differentiation within the injury-induced microenvironment would likely allow for the development of treatment strategies designed to promote the innate ability of NSCs to differentiate into neurons. The increased differentiation of neurons may contribute to relay formation, facilitating functional recovery after SCI. In this review, we summarize current strategies used to enhance the neuronal differentiation of NSCs through the reconstruction of the SCI microenvironment and to improve the intrinsic neuronal differentiation abilities of NSCs, which is significant for SCI repair.

NSCs Migration Promoted and Drug Delivered Exosomes-Collagen Scaffold via a Bio-Specific Peptide for One-Step Spinal Cord Injury Repair.

Spinal cord injury (SCI) is plaguing medical professionals globally due to the complexity of injury progression. Based on tissue engineering technology, there recently emerges a promising way by integrating drugs with suitable scaffold biomaterials to mediate endogenous neural stem cells (NSCs) to achieve one-step SCI repair. Herein, exosomes extracted from human umbilical cord-derived mesenchymal stem cells (MExos) are found to promote the migration of NSCs in vitro/in vivo. Utilizing MExos as drug delivery vehicles, a NSCs migration promoted and paclitaxel (PTX) delivered MExos-collagen scaffold is designed via a novel dual bio-specificity peptide (BSP) to effectively retain MExos within scaffolds. By virtue of the synergy that MExos recruit endogenous NSCs to the injured site, and PTX induce NSCs to give rise to neurons, this multifunctional scaffold has shown superior performance for motor functional recovery after complete SCI in rats by enhancing neural regeneration and reducing scar deposition. Besides, the dual bio-specific peptide demonstrates the capacity of tethering other cells-derived exosomes on collagen scaffold, such as erythrocytes-derived or NSCs-derived exosomes on collagen fibers or membranes. The resulting exosomes-collagen scaffold may serve as a potential multifunctional therapy modality for various disease treatments including SCI.

Proteomic analysis of aqueous humor from cataract patients with retinitis pigmentosa.

A postcataract surgery complication in patients with retinitis pigmentosa (RP) is lens capsular contraction. To identify potential proteins contributing to this phenomenon, high-performance liquid chromatography/mass spectrometry-based proteomic analysis was conducted with aqueous humor samples collected from 11 patients who underwent cataract surgeries, with four patients diagnosed as RP and cataract (RP group) and the other seven with only senile cataract group. The upregulated proteins in the RP group were enriched in wound response, while downregulated proteins were enriched in cell adhesion and lens crystallins. Receptors of two dramatically upregulated proteins tenascin-C (TNC) and serotransferrin were found expressed in human lens epithelial cells (HLEs). TNC can promote primary HLEs proliferation and cell line HLE-B3 migration. This study indicates aqueous humor proteomic analysis serves as an effective way to unveil the pathogenesis of RP complications. TNC is a potential target of stimulating HLEs proliferation in RP concomitant cataract patients that worth further research.

Efficacy of 0.5% Levofloxacin and 5.0% Povidone-Iodine Eyedrops in Reducing Conjunctival Bacterial Flora: Metagenomic Analysis.

Bacteria associated with postoperative endophthalmitis mostly originate from the normal bacterial flora of the patient's conjunctiva and eyelids, so the incidence of endophthalmitis may be reduced by eliminating the ocular and adnexal flora before surgery. We assessed the effectiveness of eyedrops of 0.5% levofloxacin and 5.0% povidone-iodine (PVI) in reducing conjunctival bacterial flora by metagenomic analysis. A total of 2.4 × 106 high-quality sequencing reads were generated from 93 conjunctival samples obtained from 31 eyes scheduled for cataract surgery before prophylactic therapy (group 1), after administration of 0.5% levofloxacin eyedrops into the conjunctival sac 8 times before surgery (group 2), and at 3 minutes after instillation of 5.0% PVI solution in the conjunctival sac (group 3) followed by surgery irrigation. The alpha diversity and beta diversity results demonstrated that group 3 had the least richness and biodiversity. Corynebacterium, Pseudomonas, Staphylococcus, Acinetobacter, and Streptococcus were predominant in all samples. The relative abundance of these bacterial species was 30.94%, 27.48%, 5.26%, 4.55%, and 2.61% in group 1, 16.32%, 44.10%, 2.19%, 5.39%, and 0.97% in group 2, and 5.90%, 65.55%, 0.39%, 5.36%, and 0.10% in group 3, respectively. The most easily and difficultly eliminated were Corynebacterium and Pseudomonas, respectively. In conclusion, the metagenomic analysis using high-throughput sequencing provides a scientific way for evaluating the effectiveness of a disinfection method from the perspective of analyzing the composition and diversity of the conjunctival microbiome. Despite the use of preoperative antisepsis regimens, the ocular surface of patients receiving cataract surgery could not be rendered completely aseptic, indicating that more strict disinfection methods need to be adopted to reduce the risk for anterior chamber contamination and endophthalmitis after cataract surgery.

Epidermal growth factor receptor-extracellular-regulated kinase blockade upregulates TRIM32 signaling cascade and promotes neurogenesis after spinal cord injury.

Nerve regeneration is blocked after spinal cord injury (SCI) by a complex myelin-associated inhibitory (MAI) microenvironment in the lesion site; however, the underlying mechanisms are not fully understood. During the process of neural stem cell (NSC) differentiation, pathway inhibitors were added to quantitatively assess the effects on neuronal differentiation. Immunoprecipitation and lentivirus-induced overexpression were used to examine effects in vitro. In vivo, animal experiments and lineage tracing methods were used to identify nascent neurogenesis after SCI. In vitro results indicated that myelin inhibited neuronal differentiation by activating the epidermal growth factor receptor (EGFR)-extracellular-regulated kinase (ERK) signaling cascade. Subsequently, we found that tripartite motif (TRIM) 32, a neuronal fate-determining factor, was inhibited. Moreover, inhibition of EGFR-ERK promoted TRIM32 expression and enhanced neuronal differentiation in the presence of myelin. We further demonstrated that ERK interacts with TRIM32 to regulate neuronal differentiation. In vivo results indicated that EGFR-ERK blockade increased TRIM32 expression and promoted neurogenesis in the injured area, thus enhancing functional recovery after SCI. Our results showed that EGFR-ERK blockade antagonized MAI of neuronal differentiation of NSCs through regulation of TRIM32 by ERK. Collectively, these findings may provide potential new targets for SCI repair.

Heparan sulfate proteoglycan promotes fibroblast growth factor-2 function for ischemic heart repair.

It is well known that the basic fibroblast growth factor (bFGF) promotes angiogenesis after myocardial infarction (MI), but its biological functions decrease in the event of diffusion, enzymolysis, and weak binding with co-receptors in vivo. Heparan sulfate proteoglycans (HSPG) are a major component of extracellular matrices and have been shown to regulate a wide range of cellular functions and bioprocesses by acting as a co-receptor for bFGF and affecting its bioactivities. However, the influence of HSPG on the function of bFGF after myocardial infarction is unknown. Here, exogenous HSPG along with bFGF was injected into the hearts of rats to deliver the angiogenic growth factor for ischemic heart repair following induced MI. The specific binding of HSPG with bFGF protein was demonstrated, which was about 6-fold stronger than the binding of bFGF with heparin. The biological mechanisms of HSPG binding with bFGF were further studied by cell adhesion assay, and assays of bFGF and matrix metalloproteinase 2 (MMP2) activities demonstrated that HSPG enhances cell adhesion, promotes the bioactivity of bFGF in angiogenesis, and protects bFGF from enzymolysis. Our results indicate that HSPG has potential clinical utility as a delivery agent for heparin-binding growth factors. Additionally, HSPG shows high binding affinities with different ECM proteins which also help to anchor bFGF to heart tissue. Therefore, extracellular proteins that mimic the bio-scaffold of the extracellular matrix could promote the activities of bFGF to facilitate ischemic heart repair.

Myocardial-Infarction-Responsive Smart Hydrogels Targeting Matrix Metalloproteinase for On-Demand Growth Factor Delivery.

Although in situ restoration of blood supply to the infarction region and attenuating pre-existing extracellular matrix degradation remain potential therapeutic approaches for myocardial infarction (MI), local delivery of therapeutics has been limited by low accumulation (inefficacy) and unnecessary diffusion (toxicity). Here, a dual functional MI-responsive hydrogel is fabricated for on-demand drug delivery to promote angiogenesis and inhibit cardiac remodeling by targeting upregulated matrix metalloproteinase-2/9 (MMP-2/9) after MI. A glutathione (GSH)-modified collagen hydrogel (collagen-GSH) is prepared by conjugating collagen amine groups with GSH sulfhydryl groups and the recombinant protein GST-TIMP-bFGF (bFGF: basic fibroblast growth factor) by fusing bFGF with glutathione-S-transferase (GST) and MMP-2/9 cleavable peptide PLGLAG (TIMP). Specific binding between GST and GSH significantly improves the amount of GST-TIMP-bFGF loaded in collagen-GSH hydrogel. The TIMP peptide enclosed between GST and bFGF responds to MMPs for on-demand release during MI. Additionally, the TIMP peptide is a competitive substrate of MMPs that inhibits the excessive degradation of cardiac matrix by MMPs after MI. GST-TIMP-bFGF/collagen-GSH hydrogels promote the recovery of MI rats by enhancing vascularization and ameliorating myocardium remodeling. The results suggest that on-demand growth factor delivery by synchronously controlling binding and responsive release to promote angiogenesis and attenuate cardiac remodeling might be promising for the treatment of ischemic heart disease.

Vascular endothelial growth factor activates neural stem cells through epidermal growth factor receptor signal after spinal cord injury.

AIMS: Neural stem cells (NSCs) in the adult mammalian spinal cord are activated in response to spinal cord injury (SCI); however, mechanisms modulating this process are not clear. Here, we noticed SCI elevated expression of vascular endothelial growth factor (VEGF) and we aimed to validate the roles of VEGF in NSCs activation after SCI and investigated the related signals during the process. METHODS: In vitro we detected whether VEGF promoted spinal cord NSCs proliferation and investigated the involved signals; In vivo, we injected VEGF into rat spinal cord to check the NSCs activation. RESULTS: In vitro, VEGF triggered spinal cord NSCs proliferation and maintained self-renewal. Further investigations demonstrated VEGF transactivated epidermal growth factor receptor (EGFR) through VEGF receptor 2 (VEGFR2) to promote spinal cord NSCs proliferation. In vivo, we injected VEGF into spinal cord by laminectomy to confirm the roles of VEGF-VEGFR2-EGFR signals in NSCs activation. VEGF significantly elevated the number of activated NSCs and increased EGFR phosphorylation. In contrast, intraspinal injection of specific inhibitors targeting EGFR and VEGFR2 decreased NSCs activation after SCI. Our results demonstrate that VEGF-VEGFR2-EGFR axis is important for NSCs activation after SCI, providing new insights into the mechanisms of spinal cord NSCs activation postinjury.

A collagen microchannel scaffold carrying paclitaxel-liposomes induces neuronal differentiation of neural stem cells through Wnt/ß-catenin signaling for spinal cord injury repair.

Neural stem cells (NSCs) show potential for spinal cord injury (SCI) repair. However, the current challenge is to direct their differentiation into neurons in the lesion site. It has been demonstrated that transplanted NSCs primarily differentiated into astrocytes rather than neurons due to the adverse microenvironment. It was reported that microtubule-stabilizing agent paclitaxel (PTX) was able to reduce scarring and enhance intrinsic axon regeneration after SCI. In this study, the effect of PTX on NSC differentiation was studied. It was demonstrated for the first time that PTX could rescue myelin-inhibited neuronal differentiation of NSCs, and induced a higher neuronal differentiation as compared with that in normal microenvironment. Enhanced neuronal differentiation in normal microenvironment further validated that PTX was capable of inducing intrinsic neuronal differentiation of NSCs. Furthermore, a functional collagen scaffold was developed by loading PTX-encapsulated liposomes into a collagen microchannel scaffold, leading to a prolonged sustained release of PTX. When NSC-laden functional collagen scaffold was implanted into T8 complete transection site of rat spinal cord, the scaffold provided an instructive microenvironment for neuronal differentiation of NSCs, motor and sensory neuron regeneration, and axon extension. The neural regeneration eventually led to improvement in motor evoked potential and hindlimb locomotion recovery. Moreover, mRNA-Seq and western blotting results revealed that PTX-triggered neuronal differentiation occurred through Wnt/ß-catenin signaling pathway. Together, the collagen microchannel scaffold in combination with sustained release of therapeutic agents for inducing neuronal differentiation of NSCs is promising for SCI repair.

Cetuximab and Taxol co-modified collagen scaffolds show combination effects for the repair of acute spinal cord injury.

Injury-activated endogenous neural stem cells (NSCs) in the spinal cord have promising therapeutic applications for rebuilding the neuronal relays after spinal cord injury (SCI) because of their lack of immune-rejection following exogenous cell transplantation. However, these NSCs rarely differentiate into neurons and the damaged axonal regenerative ability is drastically reduced due to the adverse SCI microenvironment. Cetuximab, an EGFR signaling antagonist, has demonstrated the ability of promoting NSC differentiation into neurons. Taxol, in addition to stabilizing microtubules, has shown potential for enhancing axonal regeneration and reducing scar formation after SCI. In this study, we further verified the combined therapeutic effects of Cetuximab and Taxol on inhibition of scar deposition and promotion of neuronal differentiation, axonal outgrowth and functional recovery in a rat severe SCI model. A linear orderly collagen scaffold modified with Cetuximab and Taxol was grafted into the SCI site after the complete removal of 4 mm of spinal tissue. The results showed that the combined functional scaffold implantation significantly increased neural regeneration to reconnect the neural network. Moreover, scaffold transplantation decreases the deposition of varied scar-related inhibitors within the lesion center, further reflecting the need for a combination dedicated to increasing motor function following SCI. Collagen scaffold based-combined therapy provides a potential strategy for improving functional restoration of the injured spinal cord.

Human placenta-derived mesenchymal stem cells loaded on linear ordered collagen scaffold improves functional recovery after completely transected spinal cord injury in canine.

Traumatic spinal cord injury (SCI) is a major challenge in the clinic. In this study, we sought to examine the synergistic effects of linear ordered collagen scaffold (LOCS) and human placenta-derived mesenchymal stem cells (hPMSCs) when transplanted into completely transected beagle dogs. After 36 weeks observation, we found that LOCS+hPMSCs implants promoted better hindlimb locomotor recovery than was observed in the non-treatment (control) group and LOCS group. Histological analysis showed that the regenerated tissue after treatment was well integrated with the host tissue, and dramatically reduced the volume of cystic and chondroitin sulfate proteoglycans (CSPGs) expression. Furthermore, the LOCS+hPMSCs group also showed more neuron-specific ßIII-tubulin (Tuj-1)- and NeuN-positive neurons in the lesion area, as well as axonal regeneration, remyelination and synapse formation in the lesion site. Additionally, dogs in the LOCS+hPMSCs group experienced enhanced sprouting of both ascending (CGRP-positive) sensory fibers and descending (5-HT- and TH-positive) motor fibers at the lesion area. All these data together suggested that the combined treatment had beneficial effects on neuronal regeneration and functional improvement in a canine complete transection model. Therefore, LOCS+hPMSCs implantation holds a great promise for bridging the nerve defect and may be clinically useful in the near future.

A Dual Functional Scaffold Tethered with EGFR Antibody Promotes Neural Stem Cell Retention and Neuronal Differentiation for Spinal Cord Injury Repair.

Neural stem cells (NSCs) transplantation is a promising strategy to restore neuronal relays and neurological function of injured spinal cord because of the differentiation potential into functional neurons, but the transplanted NSCs often largely diffuse from the transplanted site and mainly differentiate into glial cells rather than neurons due to the adverse microenviornment after spinal cord injury (SCI). This paper fabricates a dual functional collagen scaffold tethered with a collagen-binding epidermal growth factor receptor (EGFR) antibody to simultaneously promote NSCs retention and neuronal differentiation by specifically binding to EGFR molecule expressed on NSCs and attenuating EGFR signaling, which is responsible for the inhibition of differentiation of NSCs toward neurons. Compared to unmodified control scaffold, the dual functional scaffold promotes the adhesion and neuronal differentiation of NSCs in vitro. Moreover, the implantation of the dual functional scaffold with exogenous NSCs in rat SCI model can capture and retain NSCs at the injury sites, and promote the neuronal differentiation of the retained NSCs into functional neurons, and finally dedicate to improving motor function of SCI rats, which provides a potential strategy for synchronously promoting stem cell retention and differentiation with biomaterials for SCI repair.

A modified collagen scaffold facilitates endogenous neurogenesis for acute spinal cord injury repair.

Due to irreversible neuronal loss and glial scar deposition, spinal cord injury (SCI) ultimately results in permanent neurological dysfunction. Neuronal regeneration of neural stem cells (NSCs) residing in the spinal cord could be an ideal strategy for replenishing the lost neurons and restore function. However, many myelin-associated inhibitors in the SCI microenvironment limit the ability of spinal cord NSCs to regenerate into neurons. Here, a linearly ordered collagen scaffold was used to prevent scar deposition, guide nerve regeneration and carry drugs to neutralize the inhibitory molecules. A collagen-binding EGFR antibody Fab fragment, CBD-Fab, was constructed to neutralize the myelin inhibitory molecules, which was demonstrated to promote neuronal differentiation and neurite outgrowth under myelin in vitro. This fragment could also specifically bind to the collagen and undergo sustained release from collagen scaffold. Then, the scaffolds modified with CBD-Fab were transplanted into an acute rat SCI model. The robust neurogenesis of endogenous injury-activated NSCs was observed, and these NSCs could not only differentiate into neurons but further mature into functional neurons to reconnect the injured gap. The results indicated that the modified collagen scaffold could be an ideal candidate for spinal cord regeneration after acute SCI. STATEMENTS OF SIGNIFICANCE: A linearly ordered collagen scaffold was specifically modified with collagen-binding EGFR antibody, allowed for sustained release of this EGFR neutralizing factor, to block the myelin associated inhibitory molecules and guide spinal cord regeneration along its linear fibers. Dorsal root ganglion neurons and neural stem cells induced by CBD-Fab exhibited enhanced neurite outgrowth and neuronal differentiation rate under myelin in vitro. Transplantation of the modified collagen scaffold with moderate EGFR neutralizing proteins showed greatest advantage on endogenous neurogenesis of injury-activated neural stem cells for acute spinal cord injury repair.

Characterization and functional analysis of a novel C1q-domain-containing protein in Japanese flounder (Paralichthys olivaceus).

The complement system is important in the innate immune response. C1q-domain-containing proteins have multiple functions and occur extensively in invertebrates and vertebrates. In this study, PoC1ql3 encoding a C1q-domain-containing protein in the Japanese flounder was identified. The 266-amino-acid polypeptide encoded, PoC1ql3, shares high sequence and structural similarity with orthologues in other fish and mammals. PoC1ql3 is abundantly expressed in the brain, but less in the blood, gills, and liver. Transcripts of PoC1ql3 were down-regulated in the spleen and liver 6-24 h after bacterial infection, but were significantly up-regulated after 48 h. Full-length PoC1ql3 (C1ql3-full) and its gC1q domain (C1ql3-part) were both exerted anti-Edwardsiella tarda activity. C1ql3-part bound to lipopolysaccharide and peptidoglycan, and exerted antibacterial effects against E. tarda in vivo, suggesting that C1ql3 functions as a pathogen-recognition receptor. Therefore, PoC1ql3 functions in the innate immune system, which would facilitate the investigation of the immune system in Japanese flounder.

Cadmium Induced Apoptosis in MG63 Cells by Increasing ROS, Activation of p38 MAPK and Inhibition of ERK 1/2 Pathways.

BACKGROUND/AIMS: Cadmium (Cd) induces apoptosis in different kinds of cells, including osteoblasts, both in vivo and in vitro. However, little is known about the mechanisms by which Cd induces apoptosis. METHODS: In the present study, we used the human osteosarcoma cell line MG63, which has characteristics similar to human osteoblasts, as an in vitro model to determine the cellular mechanisms by which Cd induces apoptosis. RESULTS: We found that short-term exposure to CdCl2 induced apoptosis in MG63 cells. Furthermore, the incubation of cells with CdCl2 significantly increased the level of phosphorylated p38MAPK and significantly decreased the phosphorylation of ERK1/2 in a concentration-dependent manner. Additionally, the inhibition of the phosphorylation of p38 MAPK by SB202190 protected MG63 cells from Cd-induced apoptosis. The incubation of MG63 cells with the ERK1/2 inhibitor PD98059 significantly increased apoptosis in MG63 cells. CdCl2 also significantly increased the intracellular levels of ROS. N-acetylcysteine (NAC) significantly reduced ROS levels and reversed the effects of CdCl2 on MAPK signaling. CONCLUSION: Our results suggested that Cd induced apoptosis in MG63 cells by increasing ROS, activation of p38 MAPK and inhibition of ERK1/2 pathways.