Composite Hydrogel Conduit Incorporated with Platelet-Rich Plasma Improved the Regenerative Microenvironment for Peripheral Nerve Repair.

Peripheral nerve regeneration and functional recovery remain major challenges in clinical practice. Nerve guidance conduits (NGCs) which can regulate the regenerative microenvironment are beneficial for peripheral nerve repair. Platelet-rich plasma (PRP) can secrete multiple growth factors to regulate the regenerative microenvironment. However, current administration methods of PRP are rapidly activated followed by the burst release of growth factors, causing low therapeutic efficiency in vivo. To overcome these disadvantages, a composite nerve conduit was fabricated by incorporating PRP into a gelatin methacrylate (GelMA) and sodium alginate (SA) hydrogel. The GelMA/SA-3/PRP-20 NGCs possess optimal mechanical properties, degradation rate, and superior biological performance. Importantly, GelMA/SA-3/PRP-20 NGCs achieved the sustained release of two major growth factors (VEGF-A, PDGF-BB) from PRP. Moreover, the GelMA/SA-3/PRP-20 NGCs significantly promoted the migration of Schwann cells and the neovascularization of endothelial cells in vitro. While bridging 10 mm rat sciatic nerve defects, the GelMA/SA-3/PRP-20 NGCs promoted axonal regeneration and functional recovery of peripheral nerves. Therefore, the GelMA/SA-3/PRP-20 NGCs could regulate the regenerative microenvironment by sustained release of growth factors from PRP and shed new light on the clinical application of PRP in peripheral nerve repair.

Molecular, morphological and behavioral alterations of zebrafish (Danio rerio) embryos/larvae after clorprenaline hydrochloride exposure.

Chlorprenaline hydrochloride (CLOR) is a typical representative of ß-adrenergic agonists that may be used illegally as a livestock feed additive and may have adverse impacts on the environment. In the present study, zebrafish embryos were exposed to CLOR to investigate its developmental toxicity and neurotoxicity. The results demonstrated that CLOR exposure led to adverse effects on developing zebrafish, such as morphological changes, a high heart rate, and increased body length, resulting in developmental toxicity. Moreover, the up-regulation of activities of superoxide dismutase (SOD) and catalase (CAT) and the enhancement of malondialdehyde (MDA) content illustrated that CLOR exposure activated oxidative stress in exposed zebrafish embryos. Meanwhile, CLOR exposure also caused alterations in locomotive behavior in zebrafish embryos, including an increase in acetylcholinesterase (AChE) activity. Quantitative polymerase chain reaction (QPCR) results showed that the transcription of genes related to the central nervous system (CNS) development, namely, mbp, syn2a, α1-tubulin, gap43, shha, and elavl3, indicated that CLOR exposure could lead to neurotoxicity in zebrafish embryos. These results showed that CLOR exposure could cause developmental neurotoxicity in the early stages of zebrafish development and that CLOR might induce neurotoxicity by altering the expression of neuro-developmental genes, elevating AChE activity, and activating oxidative stress.

Lycopene suppresses gastric cancer cell growth without affecting normal gastric epithelial cells.

Gastric cancer is one of the leading causes of cancer-related death worldwide. Lycopene, a natural carotenoid, has potent antioxidant activity and anti-cancer effects against several types of cancers. However, the mechanism for the anti-gastric cancer effects of lycopene remains to be fully clarified. Normal gastric epithelial cell line GES-1 and gastric cancer cell line AGS, SGC-7901, Hs746T cells were treated with different concentrations of lycopene and the effects of lycopene were compared. Lycopene specifically suppressed cell growth monitored by Real-Time Cell Analyzer, induced cell cycle arrest and cell apoptosis detected by flow cytometry, and lowered mitochondrial membrane potentials assessed by JC-1 staining of AGS and SGC-7901 cells, while did not affect those of GES-1 cells. Lycopene did not affect the cell growth of Hs746T cells harboring TP53 mutation. Further bioinformatics analysis predicted 57 genes with up-regulated expression levels in gastric cancer and decreased function in cells after lycopene treatment. Quantitative PCR and Western Blot were used to check the critical factors in the cell cycle and apoptosis signaling pathway. Lycopene decreased the high expression levels of CCNE1 and increased the levels of TP53 in AGS and SGC-7901 cells without affecting those in GES-1 cells. In summary, lycopene could effectively suppress gastric cancer cells with CCNE1-amplification, which could be a promising target therapy reagent for gastric cancer.

Biocompatible and antibacterial Flammulina velutipes-based natural hybrid cryogel to treat noncompressible hemorrhages and skin defects.

Hemorrhage, infection, and frequent replacement of dressings bring great clinical challenges to wound healing. In this work, Flammulina velutipes extract (FV) and hydroxyethyl cellulose (HEC) were chemically cross-linked and freeze-dried to obtain novel HFV cryogels (named HFVn, with n = 10, 40, or 70 corresponding to the weight percentage of the FV content), which were constructed for wound hemostasis and full-thickness skin defect repair. Systematic characterization experiments were performed to assess the morphology, mechanical properties, hydrophilic properties, and degradation rate of the cryogels. The results indicated that HFV70 showed a loose interconnected-porous structure and exhibited the highest porosity (95%) and water uptake ratio (over 2,500%) with a desirable degradation rate and shape memory properties. In vitro cell culture and hemocompatibility experiments indicated that HFV70 showed improved cytocompatibility and hemocompatibility. It can effectively mimic the extracellular matrix microenvironment and support the adhesion and proliferation of L929 cells, and its hemolysis rate in vitro was less than 5%. Moreover, HFV70 effectively induced tube formation in HUVEC cells in vitro. The results of the bacteriostatic annulus confirmed that HFV70 significantly inhibited the growth of Gram-negative E. coli and Gram-positive S. aureus. In addition, HFV70 showed ideal antioxidant properties, with the DPPH scavenging rate in vitro reaching 74.55%. In vivo rat liver hemostasis experiments confirmed that HFV70 showed rapid and effective hemostasis, with effects comparable to those of commercial gelatin sponges. Furthermore, when applied to the repair of full-thickness skin defects in a rat model, HFV70 significantly promoted tissue regeneration. Histological analysis further confirmed the improved pro-angiogenic and anti-inflammatory activity of HFV70 in vivo. Collectively, our results demonstrated the potential of HFV70 in the treatment of full-thickness skin defects and rapid hemostasis.

Antibacterial Soy Protein Isolate Prepared by Quaternization.

Soy protein isolate (SPI) is green, high-yield natural plant protein, which is widely applied in industry (packing material and adhesives) and tissue engineering. It is meaningful to improve the antibacterial property of soy protein isolate to fabricate versatile safe products to meet people's requirements. In this study, quaternized soy protein isolate (QSPI) was synthesized by the reaction between 2,3-epoxypropyltrimethylammonium chloride (EPTMAC) and SPI. The positive charged (17.8 ± 0.23 mV) quaternary ammonium groups endow the QSPI with superior antibacterial properties against multiple bacteria in vitro and in vivo. Notably, QSPI maintains its good biocompatibility and promotes bacterial-infected wound healing in rat models. Furthermore, QSPI possesses superior water solubility in a broad pH range than raw SPI. Altogether, this soy protein isolate derivative with antibacterial property and superior water solubility may extend the application of SPI in industry and tissue engineering.

Natural Flammulina velutipes-Based Nerve Guidance Conduit as a Potential Biomaterial for Peripheral Nerve Regeneration: In Vitro and In Vivo Studies.

The treatment and repair of serious peripheral nerve injuries remain challenging in the clinical practice, while the application of multifunctional nerve guidance conduits (NGCs) based on naturally derived polymers has attracted much attention in recent years because of their excellent physicochemical properties and biological characteristics. Flammulina velutipes (Curt. ex FV) is a popular edible mushroom characterized by hollow tubular structures, antibacterial activities, and high nutritional properties. In this study, FV is utilized to construct NGCs (labeled FVC) via a freeze-drying technique without chemical modifications. The morphology, physical properties, cellular biocompatibility, antibacterial properties, and nerve regeneration capacity of FVC were assessed both in vitro and in vivo. FVC is composed of hollow tubes and evenly irregular interconnected micropores with 73.8 ± 5.5% porosity and 476.1 ± 12.9 µm hollow tube diameter. The inner surface of the FVC presents multiple microgrooves elongated parallel to the long axis. Moreover, FVC possessed strong antibacterial activity and could inhibit Gram-positive Staphylococcus aureus growth by up to 96.0% and Gram-negative Escherichia coli growth by up to 94.8% in vitro. FVC exhibited excellent biocompatibility and effectively promoted PC-12 cell proliferation and elongation in vitro. When applied to repair critical-sized sciatic nerve defects, FVC could effectively stimulate nerve functional recovery and axonal outgrowth in a rat model. Interestingly, Western blot analysis indicated that growth-associated protein 43 (GAP-43) had increased expression levels in the FVC group compared with the autograft group. This result suggested that by activating the Janus activated kinase2 (JAK2)/Phosphorylation ofsignal transducer and activator of transcription-3 (STAT3) signaling pathway, FVC upregulated Phosphorylation of signal transducer and activator of transcription-3 (P-STAT3) in vivo, resulting in the secretion of GAP-43. Collectively, a natural NGC FVC was fabricated based on FV without chemical modifications. The morphology, physical properties, cellular biocompatibility, antibacterial properties, and nerve regeneration capacity of FVC provide new insights for its further optimization and application in the field of nerve tissue engineering.

IL-17F depletion accelerates chitosan conduit guided peripheral nerve regeneration.

Peripheral nerve injury is a serious health problem and repairing long nerve deficits remains a clinical challenge nowadays. Nerve guidance conduit (NGC) serves as the most promising alternative therapy strategy to autografts but its repairing efficiency needs improvement. In this study, we investigated whether modulating the immune microenvironment by Interleukin-17F (IL-17F) could promote NGC mediated peripheral nerve repair. Chitosan conduits were used to bridge sciatic nerve defect in IL-17F knockout mice and wild-type mice with autografts as controls. Our data revealed that IL-17F knockout mice had improved functional recovery and axonal regeneration of sciatic nerve bridged by chitosan conduits comparing to the wild-type mice. Notably, IL-17F knockout mice had enhanced anti-inflammatory macrophages in the NGC repairing microenvironment. In vitro data revealed that IL-17F knockout peritoneal and bone marrow derived macrophages had increased anti-inflammatory markers after treatment with the extracts from chitosan conduits, while higher pro-inflammatory markers were detected in the Raw264.7 macrophage cell line, wild-type peritoneal and bone marrow derived macrophages after the same treatment. The biased anti-inflammatory phenotype of macrophages by IL-17F knockout probably contributed to the improved chitosan conduit guided sciatic nerve regeneration. Additionally, IL-17F could enhance pro-inflammatory factors production in Raw264.7 cells and wild-type peritoneal macrophages. Altogether, IL-17F may partially mediate chitosan conduit induced pro-inflammatory polarization of macrophages during nerve repair. These results not only revealed a role of IL-17F in macrophage function, but also provided a unique and promising target, IL-17F, to modulate the microenvironment and enhance the peripheral nerve regeneration.

Comprehensive strategy of conduit guidance combined with VEGF producing Schwann cells accelerates peripheral nerve repair.

Peripheral nerve regeneration requires stepwise and well-organized establishment of microenvironment. Since local delivery of VEGF-A in peripheral nerve repair is expected to promote angiogenesis in the microenvironment and Schwann cells (SCs) play critical role in nerve repair, combination of VEGF and Schwann cells may lead to efficient peripheral nerve regeneration. VEGF-A overexpressing Schwann cells were established and loaded into the inner wall of hydroxyethyl cellulose/soy protein isolate/polyaniline sponge (HSPS) conduits. When HSPS is mechanically distorted, it still has high durability of strain strength, thus, can accommodate unexpected strain of nerve tissues in motion. A 10 mm nerve defect rat model was used to test the repair performance of the HSPS-SC (VEGF) conduits, meanwhile the HSPS, HSPS-SC, HSPS-VEGF conduits and autografts were worked as controls. The immunofluorescent co-staining of GFP/VEGF-A, Ki67 and MBP showed that the VEGF-A overexpressing Schwann cells could promote the proliferation, migration and differentiation of Schwann cells as the VEGF-A was secreted from the VEGF-A overexpressing Schwann cells. The nerve repair performance of the multifunctional and flexible conduits was examined though rat behavioristics, electrophysiology, nerve innervation to gastrocnemius muscle (GM), toluidine blue (TB) staining, transmission electron microscopy (TEM) and NF200/S100 double staining in the regenerated nerve. The results displayed that the effects on the repair of peripheral nerves in HSPS-SC (VEGF) group was the best among the conduits groups and closed to autografts. HSPS-SC (VEGF) group exhibited notably increased CD31+ endothelial cells and activation of VEGFR2/ERK signaling pathway in the regenerated nerve tissues, which probably contributed to the improved nerve regeneration. Altogether, the comprehensive strategy including VEGF overexpressing Schwann cells-mediated and HSPS conduit-guided peripheral nerve repair provides a new avenue for nerve tissue engineering.

Green fabrication of seedbed-like Flammulina velutipes polysaccharides-derived scaffolds accelerating full-thickness skin wound healing accompanied by hair follicle regeneration.

A novel seedbed-like scaffold was firstly fabricated by the "frozen sectioning" processing method using Flammulina velutipes as a raw material. The Flammulina velutipes polysaccharides scaffold is composed of a natural structure imitating the "ground" (connected and aligned hollow tubes with porous walls). Meanwhile, its biologically active components include polysaccharides and proteins, mimicking the "plant nutrition" in the seedbed. To further optimize the ground and nutrition components, Flammulina velutipes polysaccharides-derived scaffolds (FPDSs) were fabricated via the treatment of original Flammulina velutipes polysaccharides scaffold (labeled FPS) by NaOH, cysteine (labeled as FPS/NaOH, FPS/Cys, respectively). FPDSs were characterized by SEM, FTIR, XRD, water absorption and retention, and mechanical evaluations. From the results, FPS/NaOH and FPS/Cys lost the characteristic big tubes of original strips and had higher water absorption capacities comparing to FPS. Simultaneously, FPS/NaOH had better ductility, FPS/Cys had showed increased stiffness. Biological activities of FPDSs were tested against different types of bacteria exhibiting excellent anti-bacterial activity, and FPS/NaOH and FPS/Cys had dramatically higher anti-bacterial activity than FPS. The cytocompatibility of FPDSs was evaluated utilizing mouse fibroblast cell line (L929), and all FPDSs showed good cytocompatibility. The FPDSs were further applied to a rat full-thickness skin wound model, and they all exhibited obviously accelerated re-epithelialization, among which FPS/NaOH showed the greatest efficiency. FPS/NaOH could shorten the wound-healing process as evidenced by dynamic alterations of the expression levels of specific stagewise markers in the healing areas. Similarly, FPS/NaOH can efficiently induce hair follicle regeneration in the healing skin tissues. In summary, FPDSs exhibit potential functions as seedbeds to promote the regeneration of the "seed" including hair follicles and injured skin, opening a new avenue for wound healing.

Brain Derived Neurotrophic Factor and Glial Cell Line-Derived Neurotrophic Factor-Transfected Bone Mesenchymal Stem Cells for the Repair of Periphery Nerve Injury.

Peripheral nerve injury is a common clinical neurological disease. In our previous study, highly oriented poly (L-lactic acid) (PLLA)/soy protein isolate (SPI) nanofiber nerve conduits were constructed and exhibited a certain repair capacity for peripheral nerve injury. In order to further improve their nerve repairing efficiency, the bone mesenchymal stem cells (BMSCs) overexpressing brain derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) were introduced into the conduits as seed cells and then were used to repair the 10-mm sciatic nerve defects in rats. The nerve repair efficiency of the functional nerve conduits was evaluated by gait experiment, electrophysiological test, and a series of assays such as hemotoxylin-eosin (HE) staining, immunofluorescence staining, toluidine blue (TB) staining, transmission electron microscopy (TEM) observation of regenerated nerve and Masson's trichrome staining of gastrocnemius muscle. The results showed that the conduits containing BMSCs overexpressing BDNF and GDNF double-factors group had better nerve repairing efficiency than blank BMSCs and single BDNF or GDNF factor groups, and superior to autografts group in some aspects. These data demonstrated that BDNF and GDNF produced by BMSCs could synergistically promote peripheral nerve repair. This study shed a new light on the conduits and stem cells-based peripheral nerve repair.

Aligned soy protein isolate-modified poly(L-lactic acid) nanofibrous conduits enhanced peripheral nerve regeneration.

OBJECTIVE: Repair and regeneration of peripheral nerve defect by engineered conduits have greatly advanced in the past decades while still facing great challenges. APPROACH: In this work, we fabricated a new highly oriented poly(L-lactic acid) (PLLA)/soy protein isolate (SPI) nanofibrous conduit (HO-PSNC) for nerve regeneration. MAIN RESULTS: Firstly, we observed that SPI could efficiently modify PLLA for the electrospinning of PLLA/SPI nanofibers with enhanced physical and biological properties. Incorporation of SPI decreased the fiber diameter and ductility of PLLA/SPI nanofibrous films (PSNFs), improved the tensile strength and surface wettability of PSNFs and increased the in vivo degradability of the PSNFs. When the hybrid ratio of SPI was 20 and 40%, PSNFs could efficiently promote neural cell extension and differentiation in vitro. Based on these data, 20% SPI (PSNF-20) was chosen for further investigation. Next, PSNF-20 with different fiber orientations (random/low orientation, medium, and high orientation, respectively) were developed and used for evaluating neural cell behaviors on the materials. Results revealed that the PSNF-20 with highly oriented nanofibers (HO-PSNF-20) or mediumly oriented nanofibers (MO-PSNF-20) showed a better performance in directing cell extension and enhancing neurite outgrowth. Finally, the highly oriented nanofibers conduits (HO-PSNC-20) were used to bridge sciatic nerve defect in rats with highly oriented PLLA and autografts as controls. HO-PSNC-20 exhibited a significant promotion in nerve regeneration and functional reconstruction comparing to highly oriented PLLA as proven by the evaluations of walking track, electrophysiology, toluidine blue nerve staining, transmission electron microscopy, neural factors staining and qPCR, and gastrocnemius histology. SIGNIFICANCE: In conclusion, nerve conduit fabricated from aligned electrospinning of SPI-modified PLLA nanofibers is promising for peripheral nerve regeneration.

Divergent effects of lycopene on pancreatic alpha and beta cells.

Lycopene is an antioxidant which has potential anti-diabetic activity, but the cellular mechanisms have not been clarified. In this study, different concentrations of lycopene were used to treat pancreatic alpha and beta cell lines, and the changes of cell growth, cell apoptosis, cell cycle, reactive oxygen species (ROS), ATP levels and expression of related cytokines were determined. The results exhibited that lycopene did not affect cell growth, cell apoptosis, cell cycle, ROS and ATP levels of alpha cells, while it promoted the growth of beta cells, increased the ratio of S phase, reduced the ROS levels and increased the ATP levels of beta cells. At the same time, lycopene treatment elevated the mRNA expression levels of tnfα, tgfß and hif1α in beta cells. These findings suggest that lycopene plays cell-specific role and activates pancreatic beta cells, supporting its application in diabetes therapy.

Transcription factor c-Maf is a checkpoint that programs macrophages in lung cancer.

Macrophages have been linked to tumor initiation, progression, metastasis, and treatment resistance. However, the transcriptional regulation of macrophages driving the protumor function remains elusive. Here, we demonstrate that the transcription factor c-Maf is a critical controller for immunosuppressive macrophage polarization and function in cancer. c-Maf controls many M2-related genes and has direct binding sites within a conserved noncoding sequence of the Csf-1r gene and promotes M2-like macrophage-mediated T cell suppression and tumor progression. c-Maf also serves as a metabolic checkpoint regulating the TCA cycle and UDP-GlcNAc biosynthesis, thus promoting M2-like macrophage polarization and activation. Additionally, c-Maf is highly expressed in tumor-associated macrophages (TAMs) and regulates TAM immunosuppressive function. Deletion of c-Maf specifically in myeloid cells results in reduced tumor burden with enhanced antitumor T cell immunity. Inhibition of c-Maf partly overcomes resistance to anti-PD-1 therapy in a subcutaneous LLC tumor model. Similarly, c-Maf is expressed in human M2 and tumor-infiltrating macrophages/monocytes as well as circulating monocytes of human non-small cell lung carcinoma (NSCLC) patients and critically regulates their immunosuppressive activity. The natural compound ß-glucan downregulates c-Maf expression on macrophages, leading to enhanced antitumor immunity in mice. These findings establish a paradigm for immunosuppressive macrophage polarization and transcriptional regulation by c-Maf and suggest that c-Maf is a potential target for effective tumor immunotherapy.

Gastric cancer patients have elevated plasmacytoid and CD1c+ dendritic cells in the peripheral blood.

Dendritic cells (DCs) are important in tumor immunology. Identifying DC subset markers in the peripheral blood, which are informative for gastric cancer stages, is not only useful for prognosis but may also provide mechanistic insights into processes facilitating therapy. The present study investigated plasmacytoid dendritic cells (pDCs) and myeloid CD1c+ dendritic cells (mDC1s) in the peripheral blood of patients with gastric cancer and healthy controls using flow cytometry. Using peripheral DC staining and subset analysis, patients with gastric cancer were identified to have substantially higher numbers of peripheral pDCs and mDC1s. In addition, there was a trend of elevated circulating pDCs with advanced stages and lymph node metastasis in gastric cancer, whereas no differences in circulating mDC1s were observed among the various groups. The results suggested that circulating pDCs are a positive prognostic indicator in patients with gastric cancer of different stages and highlighted the critical role of pDCs immunity in the development of gastric cancer.

Electrodeposition to construct mechanically robust chitosan-based multi-channel conduits.

A series of electrodeposited chitosan-based multi-channel conduits (ECMC) with potential for peripheral nerve tissue engineering were constructed using a novel electrodeposition method combined with homemade molds. The structural and mechanical properties of the ECMC were characterized by scanning electron microscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction patterns and mechanical testing. The results showed that the electrodeposition process did not change the chemical structure of the chitosan molecules, but endowed the ECMC with high levels of flexibility and elasticity. Hemocompatibility and cytocompatibility of the ECMC were evaluated by hemolysis assay, MTT assay and live/dead assay. The results indicated that the ECMC had a low hemolysis rate, and can promote cell proliferation and support cell adhesion. This work provides a safe and feasible electrodeposition method to construct chitosan-based conduits with potential applications for peripheral nerve tissue engineering.

Innate γδT17 cells play a protective role in DSS-induced colitis via recruitment of Gr-1+CD11b+ myeloid suppressor cells.

Innate γδ T cells play critical roles in mucosal immunity such as regulating intestinal epithelial homeostasis. In addition, γδ T cells are significantly increased in the inflamed mucosa of patients with ulcerative colitis. However, γδ T cells are a heterogeneous population. IL-17-producing versus IFNγ-producing γδ T cells play differential roles in different disease settings. Therefore, dissecting the exact role of different subsets of γδ T cells in colitis is essential for understanding colitis immunopathogenesis. In the current study, we found that TCR δ-deficient mice had a more severe dextran sodium sulfate (DSS)-induced colitis that was reduced upon reconstitution of γδT17 cells but not IFNγ-producing γδ T cells. Immunophenotyping of the cellular infiltrate upon DSS-induced colitis showed a reduced infiltration of Gr-1+CD11b+ myeloid cells into the sites of inflammation in mice lacking γδT17 cells. Further experiments demonstrated that IL-17, IL-18, and chemokine CXCL5 were critical in Gr-1+CD11b+ myeloid cell recruitment. In vitro T cell suppressive assay indicated that this Gr-1+CD11b+ population was immunosuppressive. Depletion of Gr-1+CD11b+ myeloid cells resulted in an increase severity of DSS-induced colitis. Our study elucidates a new immune pathway involving γδT17-dependent recruitment of Gr-1+CD11b+ myeloid cells to the site of colitis inflammation important in the protection of colitis initiation and progression.

Cellulose/soy protein composite-based nerve guidance conduits with designed microstructure for peripheral nerve regeneration.

OBJECTIVE: The objective of this work was to develop nerve guidance conduits from natural polymers, cellulose and soy protein isolate (SPI), by evaluating the effects of cellulose/SPI film-based conduit (CSFC) and cellulose/SPI sponge-based conduit (CSSC) on regeneration of nerve defects in rats. APPROACH: CSFC and CSSC with the same chemical components were fabricated from cellulose and SPI. Effects of CSSC and CSFC on regeneration of the defective nerve were comparatively investigated in rats with a 10 mm long gap in sciatic nerve. The outcomes of peripheral nerve repair were evaluated by a combination of electrophysiological assessment, Fluoro-Gold retrograde tracing, double NF200/S100 immunofluorescence analysis, toluidine blue staining, and electron microscopy. The probable molecular mechanism was investigated using quantitative real-time PCR (qPCR) analysis. MAIN RESULTS: Compared with CSFC, CSSC had 2.69 times higher porosity and 5.07 times higher water absorption, thus ensuring much higher permeability. The nerve defects were successfully bridged and repaired by CSSC and CSFC. Three months after surgery, the CSSC group had a higher compound muscle action potential amplitude ratio, a higher percentage of positive NF200 and S100 staining, and a higher axon diameter and myelin sheath thickness than the CSFC group, showing the repair efficiency of CSSC was higher than that of CSFC. qPCR analysis indicated the mRNA levels of nerve growth factor, IL-10, IL-6, and growth-associated protein 43 (GAP-43) were higher in the CSSC group. This also indicated that there was better nerve repair with CSSC due to the higher porosity and permeability of CSSC providing a more favourable microenvironment for nerve regeneration than CSFC. SIGNIFICANCE: A promising nerve guidance conduit was developed from cellulose/SPI sponge that showed potential for application in the repair of nerve defect. This work also suggests that nerve guidance conduits with better repair efficiency could be developed through structure design and processing optimization.

Hypoglycemic activity of the Baker's yeast ß-glucan in obese/type 2 diabetic mice and the underlying mechanism.

SCOPE: ß-Glucans have been shown to reduce the risk of obesity and diabetes. However, they often contain diverse polysaccharides and other ingredients, leading to elusive experimental data and mechanisms. In this study, a pure ß-glucan was obtained from the crude Baker's yeast polysaccharides for investigating its effect on the metabolic disorders in high-fat diet induced obese (DIO)/type 2 diabetic (T2D) mice and the underlying mechanism. METHODS AND RESULTS: The Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy data indicated that the pure ß-glucan (BYGlc) was a linear ß-(1→3)-glucan. It was first found that the oral administration of BYGlc into T2D and DIO mice significantly downregulated the blood glucose through suppressing sodium-glucose transporter-1 expression in intestinal mucosa. Meanwhile, BYGlc promoted glycogen synthesis and inhibited fat accumulation in liver, and depressed macrophage infiltration and pro-inflammatory cytokines production measured by histochemistry/immunohistochemistry and ELISA. Additionally, BYGlc remarkably decreased Firmicutes population and increased the proportion of Akkermansia by 16S rDNA analysis. CONCLUSION: BYGlc showed hypoglycemic activity accompanied by promotion of metabolism and inhibition of inflammation in T2D/DIO mice model. The hypoglycemic mechanisms were first declared to be through suppressing sodium-glucose transporter-1 expression and possibly associated with the altered gut microbiota.

Interleukin-17A deficiency ameliorates streptozotocin-induced diabetes.

Interleukin-17 (IL-17) is a cytokine with critical functions in multiple autoimmune diseases. However, its roles in type I diabetes and the underlying mechanisms remain to be fully elucidated. In the current study, we investigated the impact of IL-17 deficiency on streptozotocin (STZ) -induced diabetes. Il-17(-/-) mice exhibited attenuated hyperglycaemia and insulitis after STZ treatment compared with control mice. The Il-17(-/-) mice had fewer CD8(+) cells infiltrating the pancreas than wild-type controls after STZ injection. Wild-type mice showed increased percentage and number of splenic CD8(+) cells and decreased Gr1(+)  CD11b(+) myeloid-derived suppressor cells (MDSC) after STZ treatment, but Il-17(-/-) mice maintained the percentages and numbers of splenic CD8(+) cells and MDSC, suggesting that IL-17 is implicated in STZ-induced cellular immune responses in the spleen. We further purified the MDSC from spleens of STZ-treated mice. Il-17(-/-) MDSC showed increased ability to suppress CD8(+) cell proliferation in vitro compared with wild-type MDSC. Transfer of MDSC to diabetic mice showed that MDSC from Il-17(-/-) mice could ameliorate hyperglycaemia. Moreover, recipients with MDSC from Il-17(-/-) mice had a decreased percentage of CD8(+) cell in the spleen compared with recipients with MDSC from wild-type mice. These data suggest that IL-17 is required in splenic MDSC function after STZ delivery. In summary, our study has revealed a pathogenic role of IL-17 in an STZ-induced diabetes model with important implications for our understanding of IL-17 function in autoimmune diseases.

Evaluation of Immune Restoration Potential of PD-1 Blockers.

The programmed death 1 (PD-1) receptor and its primary ligand (PD-L1) have crucial roles in tumor-induced immune suppression. PD-1/PD-L1 blockers are designed to restore the immune system and induce potent antitumor effects. In this study we established a direct and reliable method to evaluate the immune restoration potential of human PD-1 blockers. We found anti-human PD-1 antibody could reverse PD-L1 induced suppression of human CD3+ cells proliferation and IL-2 production. This method is suitable for all kinds of PD-1 blockers including antibodies and chemical drugs. This function assay could be easily applied and provide valuable information for drug development.