One HA stalk topping multiple heads as a novel influenza vaccine.

Classic chimeric hemagglutinin (cHA) was designed to induce immune responses against the conserved stalk domain of HA. However, it is unclear whether combining more than one HA head domain onto one stalk domain is immunogenic and further induce immune responses against influenza viruses. Here, we constructed numerous novel cHAs comprising two or three fuzed head domains from different subtypes grafted onto one stalk domain, designated as cH1-H3, cH1-H7, cH1-H3-H7, and cH1-H7-H3. The three-dimensional structures of these novel cHAs were modelled using bioinformatics simulations. Structural analysis showed that the intact neutralizing epitopes were exposed in cH1-H7 and were predicted to be immunogenic. The immunogenicity of the cHAs constructs was evaluated in mice using a chimpanzee adenoviral vector (AdC68) vaccine platform. The results demonstrated that cH1-H7 expressed by AdC68 (AdC68-cH1-H7) induced the production of high levels of binding antibodies, neutralizing antibodies, and hemagglutinin inhibition antibodies against homologous pandemic H1N1, drifted seasonal H1N1, and H7N9 virus. Moreover, vaccinated mice were fully protected from a lethal challenge with the aforementioned influenza viruses. Hence, cH1-H7 cHAs with potent immunogenicity might be a potential novel vaccine to provide protection against different subtypes of influenza virus.

Magnetic PiezoBOTs: a microrobotic approach for targeted amyloid protein dissociation.

Piezoelectric nanomaterials have become increasingly popular in the field of biomedical applications due to their high biocompatibility and ultrasound-mediated piezocatalytic properties. In addition, the ability of these nanomaterials to disaggregate amyloid proteins, which are responsible for a range of diseases resulting from the accumulation of these proteins in body tissues and organs, has recently gained considerable attention. However, the use of nanoparticles in biomedicine poses significant challenges, including targeting and uncontrolled aggregation. To address these limitations, our study proposes to load these functional nanomaterials on a multifunctional mobile microrobot (PiezoBOT). This microrobot is designed by coating magnetic and piezoelectric barium titanate nanoparticles on helical biotemplates, allowing for the combination of magnetic navigation and ultrasound-mediated piezoelectric effects to target amyloid disaggregation. Our findings demonstrate that acoustically actuated PiezoBOTs can effectively reduce the size of aggregated amyloid proteins by over 80% in less than 10 minutes by shortening and dissociating constituent amyloid fibrils. Moreover, the PiezoBOTs can be easily magnetically manipulated to actuate the piezocatalytic nanoparticles to specific amyloidosis-affected tissues or organs, minimizing side effects. These biocompatible PiezoBOTs offer a promising non-invasive therapeutic approach for amyloidosis diseases by targeting and breaking down protein aggregates at specific organ or tissue sites.

Cytomodulin-10 modified GelMA hydrogel with kartogenin for in-situ osteochondral regeneration.

The incidence of osteochondral defect is increasing year by year, but there is still no widely accepted method for repairing the defect. Hydrogels loaded with bioactive molecules have provided promising alternatives for in-situ osteochondral regeneration. Kartogenin (KGN) is an effective and steady small molecule with the function of cartilage regeneration and protection which can be further boosted by TGF-ß. However, the high cost, instability, and immunogenicity of TGF-ß would limit its combined effect with KGN in clinical application. In this study, a composite hydrogel CM-KGN@GelMA, which contained TGF-ß1 analog short peptide cytomodulin-10 (CM-10) and KGN, was fabricated. The results indicated that CM-10 modified on GelMA hydrogels exerted an equivalent role in enhancing chondrogenesis as TGF-ß1, and this effect was also boosted when combined with KGN. Moreover, it was revealed that CM-10 and KGN had a synergistic effect on promoting the chondrogenesis of BMSCs by up-regulating the expression of RUNX1 and SOX9 at both mRNA and protein levels in vitro. Finally, the composite hydrogel exhibited a satisfactory osteochondral defect repair effect in vivo, showing similar structures close to the native tissue. Taken together, this study has revealed that CM-10 may serve as an alternative for TGF-ß1 and can collaborate with KGN to accelerate chondrogenesis, which suggests that the fabricated CM-KGN@GelMA composite hydrogel can be acted as a potential scaffold for osteochondral defect regeneration. STATEMENT OF SIGNIFICANCE: Kartogenin and TGF-ß have shown great value in promoting osteochondral defect regeneration, and their combined application can enhance the effect and show great potential for clinical application. Herein, a functional CM-KGN@GelMA hydrogel was fabricated, which was composed of TGF-ß1 mimicking peptide CM-10 and KGN. CM-10 in hydrogel retained an activity like TGF-ß1 to facilitate BMSC chondrogenesis and exhibited boosting chondrogenesis by up-regulating RUNX1 and SOX9 when being co-applied with KGN. In vivo, the hydrogel promoted cartilage regeneration and subchondral bone reconstruction, showing similar structures as the native tissue, which might be vital in recovering the bio-function of cartilage. Thus, this study developed an effective scaffold and provided a promising way for osteochondral defect repair.

Inhibition of vascular endothelial growth factor alleviates neovascular retinopathy with regulated neurotrophic/proinflammatory cytokines through the modulation of DBI-TSPO signaling.

Diazepam binding inhibitor (DBI)-translocator protein (18kDa) (TSPO) signaling in the retina was reported to possess coordinated macroglia-microglia interactions. We investigated DBI-TSPO signaling and its correlation with vascular endothelial growth factor (VEGF), neurotrophic or inflammatory cytokines in neovascular retinopathy, and under hypoxic conditions. The vitreous expression of DBI, VEGF, nerve growth factor (NGF), and interleukin-1beta (IL-1ß) were examined in proliferative diabetic retinopathy (PDR) patients with or without anti-VEGF therapy and nondiabetic controls. Retinal DBI-TSPO signaling and the effect of the anti-VEGF agent were evaluated in a mouse model of oxygen-induced retinopathy (OIR). Interactions between Müller cell-derived VEGF and DBI, as well as cocultured microglial cells under hypoxic conditions, were studied, using Western blot, real-time RT-PCR, enzyme-linked immunosorbent assay (ELISA), flow cytometry, and immunofluorescent labeling. Results showed that vitreous levels of DBI, VEGF, NGF, and IL-1ß were significantly higher in PDR patients compared with controls, which further changed after anti-VEGF therapy. A statistical association was found between vitreous DBI and VEGF, NGF, IL-1ß, and age. The application of the anti-VEGF agent in the OIR model induced retinal expression of DBI and NGF, and attenuated inflammation and microglial cell activation. Inhibition of Müller cell-derived VEGF could increase its DBI expression under hypoxic conditions, while the DBI-TSPO signaling pathway is essential for anti-VEGF agents exerting anti-inflammatory and neuroprotective effects, as well as limiting inflammatory magnitude, promoting its neurotrophin production and anti-inflammatory (M2) polarization in microglial cells. These findings suggest the beneficial effect of anti-VEGF therapy on inflammation and neurotrophy of retinal glial cells through modulation of the DBI-TSPO signaling pathway.

Intratumoral delivery of a novel oncolytic adenovirus encoding human antibody against PD-1 elicits enhanced antitumor efficacy.

To date, diverse combination therapies with immune checkpoint inhibitors (ICIs), particularly oncolytic virotherapy, have demonstrated enhanced therapeutic outcomes in cancer treatment. However, high pre-existing immunity against the widely used adenovirus human serotype 5 (AdHu5) limits its extensive clinical application. In this study, we constructed an innovative oncolytic virus (OV) based on a chimpanzee adenoviral vector with low seropositivity in the human population, named AdC68-spE1A-αPD-1, which endows the parental OV (AdC68-spE1A-ΔE3) with the ability to express full-length anti-human programmed cell death-1 monoclonal antibody (αPD-1). In vitro studies indicated that the AdC68-spE1A-αPD-1 retained parental oncolytic capacity, and αPD-1 was efficiently secreted from the infected tumor cells and bound exclusively to human PD-1 (hPD-1) protein. In vivo, intratumoral treatment with AdC68-spE1A-αPD-1 resulted in significant tumor suppression, prolonged overall survival, and enhanced systemic antitumor memory response in an hPD-1 knockin mouse tumor model. This strategy outperformed the unarmed OV and was comparable with combination therapy with intratumoral injection of AdC68-spE1A-ΔE3 and systemic administration of commercial αPD-1. In summary, AdC68-spE1A-αPD-1 is a cost-effective approach with potential clinical applications. ‬‬‬‬.

CD271 antibody-functionalized microspheres capable of selective recruitment of reparative endogenous stem cells for in situ bone regeneration.

In the strategy of in situ bone regeneration, it used to be difficult to specifically recruit bone marrow mesenchymal stem cells (BM-MSCs) by a single marker. Recently, CD271 has been considered to be one of the most specific markers to isolate BM-MSCs; however, the effectiveness of CD271 antibodies in recruiting BM-MSCs has not been explored yet. In this study, we developed novel CD271 antibody-functionalized chitosan (CS) microspheres with the aid of polydopamine (PDA) coating to recruit endogenous BM-MSCs for in situ bone regeneration. The CS microspheres were sequentially modified with PDA and CD271 antibody through dopamine self-polymerization and bioconjugation, respectively. In vitro studies showed that the CD271 antibody-functionalized microspheres selectively captured significantly more BM-MSCs from a fluorescently labeled heterotypic cell population than non-functionalized controls. In addition, the PDA coating was critical for supporting stable adhesion and proliferation of the captured BM-MSCs. Effective early recruitment of CD271+ stem cells by the functionalized microspheres at bone defect site of SD rat was observed by the CD271/DAPI immunofluorescence staining, which led to significantly enhanced new bone formation in rat femoral condyle defect over long term. Together, findings from this study have demonstrated, for the first time, that the CD271 antibody-functionalized CS microspheres are promising for in situ bone regeneration.

Copy Number Variation Analysis of IL22 and LCE3C in Different Subtypes of Psoriasis in a Chinese Han Population.

BACKGROUND Psoriasis is a chronic, immune-mediated and hyperproliferative skin disease with both genetic and environmental components. Copy number variations (CNV) of IL22 and LCE3C-LCE3B deletion have been confirmed to be predisposed to psoriasis vulgaris (PsV) in several ethnic groups. However, it remains to be clarified whether CNVs of IL22 and LCE3C are associated with different subtypes of psoriasis (psoriatic arthritis, PsA; erythrodermic psoriasis, EP; and generalized pustular psoriasis, GPP). MATERIAL AND METHODS We enrolled 897 Han Chinese individuals, including 478 patients and 419 healthy controls, and detected CNVs of IL22 and LCE3C using the comparative CT method by real-time PCR, and Pearson's χ² test was used to evaluated the copy number difference among subtypes. RESULTS CNVs of IL22 were significantly higher in PsV than in healthy controls (P<0.001). CNV of LCE3C in PsV, PsA, and GPP groups were significantly lower compared to healthy controls. When linked with clinical parameters, mild psoriasis carried less IL22 copy numbers than that in severe psoriasis (P=0.043). Neither IL22 or LCE3C CNVs were associated with age of onset. CONCLUSIONS CNVs of LCE3C and IL22 might differentially contribute to subtypes of psoriasis. These findings suggest complex and diverse genetic variations in and among different clinical subtypes of psoriasis.

A bivalent live-attenuated vaccine candidate elicits protective immunity against human adenovirus types 4 and 7.

Human adenovirus types 4 (HAdV4) and 7 (HAdV7) often lead to severe respiratory diseases and occur epidemically in children, adults, immune deficiency patients, and other groups, leading to mild or severe symptoms and even death. However, no licensed adenovirus vaccine has been approved in the market for general use. E3 genes of adenovirus are generally considered nonessential for virulence and replication; however, a few studies have demonstrated that the products of these genes are also functional. In this study, most of the E3 genes were deleted, and two E3-deleted recombinant adenoviruses (ΔE3-rAdVs) were constructed as components of the vaccine. After E3 deletion, the replication efficiencies and cytopathogenicity of ΔE3-rAdVs were reduced, indicating that ΔE3-rAdVs were attenuated after E3 genes deletion. Furthermore, single immunization with live-attenuated bivalent vaccine candidate protects mice against challenge with wild-type human adenovirus types 4 and 7, respectively. Vaccinated mice demonstrated remarkably decreased viral loads in the lungs and less lung pathology compared to the control animals. Taken together, our study confirms the possibility of the two live-attenuated viruses as a vaccine for clinic use and illustrates a novel strategy for the construction of an adenovirus vaccine.

Stimuli-Responsive Micelles with Detachable Poly(2-ethyl-2-oxazoline) Shell Based on Amphiphilic Polyurethane for Improved Intracellular Delivery of Doxorubicin.

Polyurethanes (PUs) have various biomedical applications including controlled drug delivery. However, the incompletely release of drug at tumor sites limits the efficiency of these drug loaded polyurethane micelles. Here we report a novel polymer poly(2-ethyl-2-oxazoline)-SS-polyurethane-SS-poly(2-ethyl-2-oxazoline) triblock polyurethane (PEtOz-PU(PTMCSS)-PEtOz). The hydrophilic pH-responsive poly(2-ethyl-2-oxazoline) was used as an end-block to introduce pH responsiveness, and the hydrophobic PU middle-block was easily synthesized by the reaction of poly (trimethylene carbonate) diol containing disulfide bonds (PTMC-SS-PTMC diol) and bis (2-isocyanatoethyl) disulfide (CDI). PEtOz-PU(PTMCSS)-PEtOz could self-assemble to form micelles (176 nm). The drug release profile of PEtOz-PU(PTMCSS)-PEtOz micelles loaded with Doxorubicin (DOX) was studied in the presence of acetate buffer (10 mM, pH 5.0) and 10 mM dithiothreitol (DTT). The results showed that under this environment, DOX-loaded polyurethane micelles could release DOX faster and more thoroughly, about 97% of the DOX was released from the DOX-loaded PEtOz-PU(PTMCSS)-PEtOz micelle. In addition, fluorescent microscopy and cell viability assays validated that the DOX-loaded polyurethane micelle strongly inhibits the growth of C6 cells, suggesting their potential as a new nanomedicine against cancer.

Poly(ethylene glycol)-sheddable reduction-sensitive polyurethane micelles for triggered intracellular drug delivery for osteosarcoma treatment.

BACKGROUND: The survival rate of osteosarcoma therapy still lags behind overall cancer therapies due to the intrinsic or acquired drug resistance. Developing novel drug delivery systems that may overcome drug resistance would greatly facilitate osteosarcoma therapy. METHODS: Poly(ethylene glycol) (PEG)-sheddable reduction-sensitive polyurethane (SS-PU-SS-PEG) was synthesized using a disulfide-containing polycaprolactone diol as the hydrophobic block and a cystamine-functionalized PEG as the hydrophilic block. SS-PU-SS-PEG micelles were then prepared to load the anti-tumor drug Doxorubicin (DOX) in order to achieve triggered intracellular drug delivery to improve the efficacy of osteosarcoma therapy. RESULTS: When DOX was used as a model drug, the drug-loaded SS-PU-SS-PEG micelles were about 82∼94 nm in diameter and exhibited good stability in phosphate buffer saline (PBS). The micelles could release about 80% DOX in a quantitative fashion within 5 hours under a reductive environment. The intracellular drug release of DOX-loaded SS-PU-SS-PEG micelles increased upon incubation with Saos-2 cells in vitro. The micelles had good biocompatibility. In vitro, DOX-loaded SS-PU-SS-PEG micelles showed significant antitumor activity toward Saos-2 cells, which was close to that of free DOX. In vivo, DOX-loaded SS-PU-SS-PEG micelles exhibited better antitumor activity than free DOX. CONCLUSION: Findings from this study suggest that the SS-PU-SS-PEG micelles could achieve well-controlled triggered drug release in a reduction environment and could therefore improve the antitumor efficacy of osteosarcoma therapies. TRANSLATION POTENTIAL OF THIS ARTICLE: In this study we developed PEG-sheddable reduction-sensitive polyurethane micelles (SS-PU-SS-PEG), which were able to achieve well-controlled triggered release of anti-tumor drug Doxorubicin (DOX) in an intracellular reduction environment. DOX-loaded SS-PU-SS-PEG micelles markedly improved the antitumor efficacy in a Saos-2 cells-bearing xenograft tumor model. Therefore, such micelles might be used as a novel drug delivery system for osteosarcoma treatment.

Polydopamine-assisted surface modification for orthopaedic implants.

Along with the massive use of implants in orthopaedic surgeries in recent few decades, there has been a tremendous demand for the surface modification of the implants to avoid surgery failure and improve their function. Polydopamine (PDA), being able to adhere to almost all kinds of substrates and possessing copious functional groups for covalently immobilizing biomolecules and anchoring metal ions, has been widely used for surface modification of materials since its discovery in the last decade. PDA and its derivatives can be used for the surface modification of orthopaedic implants to modulate cellular responses, including cell spreading, migration, proliferation, and differentiation, and may thereby enhance the function of existing implants. In addition, the osseointegration and antimicrobial properties of orthopaedic implants may also be improved by PDA-based coatings. The aim of this review is to provide a brief overview of current advances of surface modification technologies for orthopaedic implants using PDA and its derivatives as a medium. Given the versatility of PDA-based adhesion, such PDA-assisted surface modification technologies will certainly benefit the development of new orthopaedic implants. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Surface treatments of orthopaedic implants, which are normally inert materials, are essential for their performance in vivo. This review summarizes recent advances in the surface modification of orthopaedic implants using facile and highly versatile techniques based on the use of polydopamine (PDA) and its derivatives.

Facile Preparation of Reduction-Responsive Micelles Based on Biodegradable Amphiphilic Polyurethane with Disulfide Bonds in the Backbone.

In this paper, we synthesized a biodegradable amphiphilic polymer of polyurethane-polyethylene glycol with disulfide bonds in the main chain (PEG-PU(SS)-PEG). DLS and SEM showed that the polymer could self-assemble into micelles in aqueous solution and could be used to load the hydrophobic anticancer drug DOX. Intriguingly, drug release in vitro indicated that DOX-loaded PEG-PU(SS)-PEG micelles had good stability under the extracellular physiological environment, but the disulfide bonds broke rapidly and DOX was released quickly under the intracellular reducing conditions. CCK-8 assays showed that DOX-loaded PEG-PU(SS)-PEG micelles had a high in vitro antitumor activity in C6 cells, whereas blank PEG-PU(SS)-PEG micelles were nontoxic to C6 cells. It was also found that there was strong and persistent accumulation of DOX-loaded PEG-PU(SS)-PEG as compared with PEG-PU-PEG both by the cell internalization tests and the flow cytometry measurements. Hence, PEG-PU(SS)-PEG micelles will have a potential use for clinical treatment of cancer in the future.

Injectable Silk-Vaterite Composite Hydrogels with Tunable Sustained Drug Release Capacity.

Improving the efficiency of chemotherapy remains a key challenge in drug delivery. Many drug carriers have been designed to achieve multifunctional factors as part of their performance, including controlled release, dispersibility in aqueous environments, and targeting to cancer sites. However, it is difficult to optimize multiple properties simultaneously for a single carrier system. Here, synergistic carriers composed of vaterite microspheres and silk nanofiber hydrogels were developed to improve the dispersibility of vaterite spheres and the control of drug delivery without compromising the injectability or sensitivity to pH. The vaterite microspheres were dispersed homogeneously and remained stable in the silk nanofiber hydrogels. Doxorubicin (DOX) was effectively loaded on the vaterite spheres and silk nanofibers, forming synergistic silk-vaterite hydrogel delivery systems. The sustained delivery of DOX was tuned and controlled by vaterite stability and the DOX content loaded on the spheres and nanofibers. The cytotoxicity was regulated via the controlled delivery of DOX, suggesting the possibility of optimizing chemotherapeutic strategies. These silk-vaterite delivery hydrogels suggest a useful strategy for designing novel delivery systems for improved delivery and therapeutic benefits.

Upregulation of SIRT1 by Kartogenin Enhances Antioxidant Functions and Promotes Osteogenesis in Human Mesenchymal Stem Cells.

Osteoarthritis is a chronic degenerative joint disease involving both articular cartilage and subchondral bone. Kartogenin (KGN) was recently identified to improve in vivo cartilage repair; however, its effect on bone formation is unknown. The aim of this study was to investigate the effect of KGN on antioxidant properties and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs). Human BM-MSCs were treated with KGN at concentrations ranging from 10-8 M to 10-6 M. Our results indicated that KGN improved cell proliferation and attenuated intracellular reactive oxygen species. The levels of antioxidant enzymes and osteogenic differentiation of BM-MSCs were enhanced by KGN in a dose-dependent manner. Furthermore, KGN-treated BM-MSCs showed upregulation of silent information regulator type 1 (SIRT1) and increased phosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK), indicating that KGN activated the AMPK-SIRT1 signaling pathway in BM-MSCs. Inhibition of SIRT1 by nicotinamide reversed the antioxidant effect of KGN on BM-MSCs and suppressed osteogenic differentiation. In conclusion, our results demonstrated that KGN improved intracellular antioxidant properties and promoted osteogenic differentiation of BM-MSCs by activating the AMPK-SIRT1 signaling pathway. Thus, KGN may have the potential for not only articular cartilage repair but also the clinical application of MSCs in bone tissue engineering.

Mutational analysis of epidermal and hyperproliferative type I keratins in mild and moderate psoriasis vulgaris patients: a possible role in the pathogenesis of psoriasis along with disease severity.

BACKGROUND: Mutations in keratin proteins have been vastly associated with a wide array of genodermatoses; however, mutations of keratins in psoriasis have not been fully investigated. The main aim of the current research was to identify the mutation in K14, K10, K16, and K17 genes in two stages of psoriasis patients. METHODS: Ninety-six psoriatic skin biopsies were collected. mRNA transcript of K14, K10, K16, and K17 was prepared, amplified, and sequenced. Sanger sequences of all keratins were further validated for mutational analysis using Mutation Surveyor and Alamut Visual. Then, in silico analysis of protein stability and protein and gene expression of all keratins was performed and validated. RESULTS: Out of 44 mutations, about 75% of keratins are highly pathogenic and deleterious. Remaining 25% mutations are less pathogenic and tolerated in nature. In these 33 deleterious mutations were immensely found to decrease keratin protein stability. We also found a correlation between keratin and Psoriasis Area and Severity Index score which added that alteration in keratin gene in skin causes severity of psoriasis. CONCLUSIONS: We strongly concluded that acanthosis and abnormal terminal differentiation was mainly due to the mutation in epidermal keratins. In turn, disease severity and relapsing of psoriasis are mainly due to the mutation of hyperproliferative keratins. These novel keratin mutations in psoriatic epidermis might be one of the causative factors for psoriasis.

Inhibition of osteoclastogenesis by stem cell-derived extracellular matrix through modulation of intracellular reactive oxygen species.

Decellularized extracellular matrix (ECM) derived from stem cells has been shown as a promising biomaterial for bone regeneration because of the promotion effect on osteogenesis in mesenchymal stem cells (MSCs). However, bone regeneration is also influenced by bone resorption and little is known about the effect of cell-derived ECM on osteoclast differentiation. In this study, ECM was deposited by MSCs and, after decellularization, the effect of ECM on osteoclastogenesis of bone marrow monocytes (BMMs) was investigated in comparison to standard tissue culture polystyrene. Our results showed that cell-derived ECM improved BMM proliferation but potently inhibited osteoclast differentiation, evidenced by down-regulation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive cells, areas of actin rings, and osteoclast-specific gene expression. ECM-mediated attenuation of intracellular reactive oxygen species (ROS) was suggested to play a rival role in the inhibition of osteoclastogenesis, because exogenous hydrogen peroxide supplementation partially rescued the ECM-inhibited osteoclastogenesis. Furthermore, rather than collagen type I, fibronectin in the ECM contributed to ECM-mediated anti-osteoclastogenesis. In conclusion, stem cell-derived decellularized ECM significantly suppressed osteoclastogenesis via the attenuation of intracellular ROS. The anti-osteoclastogenic property of cell-derived ECM may benefit its clinical use for modulating bone remodeling and promoting bone tissue engineering. STATEMENT OF SIGNIFICANCE: Decellularized extracellular matrix (ECM) derived from stem cells has been shown as a promising biomaterial for bone regeneration; however, bone remodeling is influenced by bone resorption and little is known about the effect of cell-derived ECM on osteoclast differentiation. Cell-derived ECM improved BMM proliferation but potently inhibited osteoclast differentiation. ECM-mediated attenuation of intracellular reactive oxygen species was suggested to play a rival role in osteoclastogenesis. Fibronectin in cell-derived ECM also contributed to ECM-mediated anti-osteoclastogenesis. The anti-osteoclastogenic property of cell-derived ECM may benefit clinically for modulating bone remodeling and promoting bone tissue engineering.

Bach2 regulates aberrant activation of B cell in systemic lupus erythematosus and can be negatively regulated by BCR-ABL/PI3K.

OBJECTIVE: This study was aimed to explore the effect of Bach2 on B cells in systemic lupus erythematosus (SLE), as well as the underlying mechanisms. METHODS: Expression of Bach2, phosphorylated-Bach2 (p-Bach2), Akt, p-Akt and BCR-ABL (p210) in B cells isolated from SLE patients and the healthy persons were assessed by Western blot. Immunofluorescence staining was performed to assess the localization of Bach2 in B cells. Enzyme-linked immunosorbent assay (ELISA) was employed to detect IgG produced by B cells. Cell counting kit-8 (CCK-8) and Annexin-V FITC/PI double staining assay were adopted to evaluate cell proliferation and apoptosis in B cells, respectively. RESULTS: Compared to the healthy controls, Bach2, p-Akt and p210 were significantly decreased, while nuclear translocation of Bach2, IgG, CD40 and CD86 obviously up-regulated in B cells from SLE patients. Bach2 significantly inhibited the proliferation, promoted apoptosis of B cells from SLE patients, whereas BCR-ABL dramatically reversed cell changes induced by Bach2. Besides, BCR-ABL also inhibited nuclear translocation of Bach2 in B cells from SLE patients. Further, LY294002 treatment had no effect on decreased expression of Bach2 induced by BCR-ABL, but significantly eliminated BCR-ABL-induced phosphorylation of Bach2 and restored reduced nuclear translocation of Bach2 induced by BCR-ABL in B cells from SLE. CONCLUSIONS: Bach2 may play a suppressive role in B cells from SLE, and BCR-ABL may inhibit the nuclear translocation of Bach2 via serine phosphorylation through the PI3K pathway.

SIRT1-dependent anti-senescence effects of cell-deposited matrix on human umbilical cord mesenchymal stem cells.

Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) are considered an attractive cell source for tissue regeneration. However, environmental oxidative stress can trigger premature senescence in MSCs and thus compromises their regenerative potential. Extracellular matrix (ECM) derived from MSCs has been shown to facilitate cell proliferation and multi-lineage differentiation. This investigation evaluated the effect of cell-deposited decellularized ECM (DECM) on oxidative stress-induced premature senescence in UC-MSCs. Sublethal dosages of H2 O2 , ranging from 50 µm to 200 µm, were used to induce senescence in MSCs. We found that DECM protected UC-MSCs from oxidative stress-induced premature senescence. When treated with H2 O2 at the same concentration, cell proliferation of DECM-cultured UC-MSCs was twofold higher than those on standard tissue culture polystyrene (TCPS). After exposure to 100 µm H2 O2 , fewer senescence-associated ß-galactosidase-positive cells were observed on DECM than those on TCPS (17.6  ± â€…4.0% vs. 60.4  ± â€…6.2%). UC-MSCs cultured on DECM also showed significantly lower levels of senescence-related regulators, such as p16INK4α and p21. Most importantly, DECM preserved the osteogenic differentiation potential of UC-MSCs with premature senescence. The underlying molecular mechanisms involved the silent information regulator type 1 (SIRT1)-dependent signalling pathway, confirmed by the fact that the SIRT1 inhibitor nicotinamide counteracted the DECM-mediated anti-senescent effect. Collagen type I, rather than fibronectin, partially contributed to the protective effect of decellularized matrix. These findings provide a new strategy of using stem cell-deposited matrix to overcome the challenge of cellular senescence and to facilitate the clinical application of MSCs in regenerative medicine. Copyright © 2017 John Wiley & Sons, Ltd.

Both haemagglutinin-specific antibody and T cell responses induced by a chimpanzee adenoviral vaccine confer protection against influenza H7N9 viral challenge.

Since 2013, the outbreak or sporadic infection of a new reassortant H7N9 influenza virus in China has resulted in hundreds of deaths and thousands of illnesses. An H7N9 vaccine is urgently needed, as a licensed human vaccine against H7N9 influenza is currently not available. Here, we developed a recombinant adenovirus-based vaccine, AdC68-H7HA, by cloning the H7N9 haemagglutinin (HA) gene into the chimpanzee adenoviral vector AdC68. The efficacy of AdC68-H7HA was evaluated in mice as well as guinea pigs. For comparison, an H7N9 DNA vaccine based on HA was also generated and tested in mice and guinea pigs. The results demonstrated that both AdC68-H7HA and the DNA vaccine prime-adenovirus boost regimen induced potent immune responses in animals and completely protected mice from lethal H7N9 influenza viral challenge. A post-immunization serum transfer experiment showed that antibody responses could completely protect against lethal challenge, while a T cell depletion experiment indicated that HA-specific CD8+ T cells responses also contributed to protection. Therefore, both HA-specific humoral immunity and cellular immunity play important roles in the protection. These data suggest that the chimpanzee adenovirus expressing HA is a promising vaccine candidate for H7N9 virus or other influenza viral subtypes.