Developing targeted drug delivery carriers for breast cancer using glutathione-sensitive doxorubicin-coupled glycated bovine serum albumin nanoparticles.

Incorporation of the nano-based carriers into drug delivery provides a promising alternative to overcome the limitations of the conventional chemotherapy. Doxorubicin (DOXO) is an effective chemotherapeutic drug widely used in chemotherapy for breast cancer treatment. A globular protein bovine serum albumin (BSA) holds great potential as carriers in pharmaceutical applications. This work is aimed at developing the DOXO-coupled glycated BSA nanoparticles via desolvation method for improving the capability of targeting the GLUT5 transporters over-expressed on breast cancer cells. Fructosamine assay and Fourier transform infrared spectroscopy were employed to determine the content of fructosamine structure and structural changes on the surfaces of nanoparticles, respectively. Additionally, the synthesized BSA nanoparticles were further characterized by electron microscopy and dynamic light scattering. Results revealed that the DOXO-coupled glycated BSA nanoparticles were spherically shaped with a hydrodynamic diameter of ~60.74 nm and a ζ-potential of ~ - 42.20 mV. Moreover, the DOXO release behavior of as-synthesized DOXO-coupled glycated BSA nanoparticles was examined under different conditions. Finally, the DOXO-coupled glycated BSA nanoparticles were found to exhibit cytotoxicity toward both MCF-7 and MDA-MB-231 cells. Our findings evidently suggested that the drug-coupled glycated BSA nanoparticles serve as the potential candidates for targeted drug delivery platform used in breast cancer therapy.

DNAJA3 regulates B cell development and immune function.

BACKGROUND: DnaJ homolog subfamily A member 3 (DNAJA3), also known as the tumorous imaginal disc (Tid1), is shown to be crucial in T cell development. DNAJA3 functions as a tumor suppressor implicated in lymphocyte development and survival. However, the role of DNAJA3 in B cell development and immune function remains unknown. In this study, we utilized a mouse model of B cell-specific DNAJA3 knockout (CD19-Cre/+; DNAJA3flx/flx) to investigate the physiological function of DNAJA3 in B cell development and immune function. METHODS: We characterized B cell populations in various developmental stages and examined mitochondrial content and function between control and DNAJA3 KO using flow cytometry analysis. DNAJA3 and OXPHOS protein complexes in sorted B cells between mice groups were compared using immunoblot techniques. The activity of B cell blastogenesis in splenocytes was measured by performing CFSE and MTT assays. Furthermore, immunoglobulin production was detected using the ELISA method. RESULTS: DNAJA3 deficiency decreases from pro B cells to immature B cells. The overall B220+ population in the bone marrow and secondary immune organs also decreased. B cell subpopulations B1 (B1b) and B2 significantly decrease. The B cell blastogenesis activity and immunoglobulin production decreased in DNAJA3 KO mice. Mechanistically, DNAJA3 deficiency significantly increases dysfunctional mitochondria activity and decreases mitochondrial mass, membrane potential, and mitochondria respiratory complex proteins. These factors could have influenced B cell differentiation during development, differentiation to antibody-secreting cells, and immune activation. CONCLUSION: Overall, our study provides supportive evidence for the role of DNAJA3 in B cell development and function.

Topical Application of Antrodia cinnamomea Ointment in Diabetic Wound Healing.

The number of diagnosed diabetic patients is increasing worldwide. Many people with diabetes develop wounds that are slow to, or never, heal, which can lead to serious health issues. Diabetes causes long-term excessive blood glucose buildup in human body, which leads to an over-reactive inflammatory response and excessive oxidative stress. As a result, varied wound healing effects were observed according to different circumstances and stage of healing. We used two diabetic wound animal models to analyze the wound healing effect of Antrodia cinnamomea ointment in either topical application and/or oral administration, and explored its mechanism by Western blot analysis. The results showed that topical Antrodia cinnamomea treatment can significantly promote wound healing. The increased expressions of angiopoietin 1 and angiopoietin 2 protein and reduction of CD68 expression were found around wound area. Simultaneous treatment of oral and topical Antrodia cinnamomea ointment did not show an accelerated healing effect in our animal model. This study is the first report to demonstrate the effect of topical application of Antrodia cinnamomea ointment on diabetic wounds healing, and its relationship with angiogenesis. This may also open a new field for future development and application of Taiwan Antrodia cinnamomea.

Exploring the influence of brilliant blue G on amyloid fibril formation of lysozyme.

Evidence suggests that amyloid fibril mitigation/inhibition is considered a promising approach toward treating amyloid diseases. In this work, we first examined how amyloid fibrillogenesis of lysozyme was affected by BBG, a safe triphenylmethane compound with nice blood-brain-barrier-permeability, and found that shorter fibrillar species were formed in the lysozyme samples treated with BBG. Next, alterations in the features including the secondary as well as tertiary structure, extent of aggregation, and molecular distribution of lysozyme triggered by the addition of BBG were examined by various spectroscopic techniques, right-angle light scattering, dynamic light scattering, and SDS-PAGE. In addition, we have investigated how BBG affected the lysozyme fibril-induced cytotoxicity in SH-SY5Y cells. We found that a large quantity of shorter fibrillar species and more lysozyme monomers were present in the samples treated with BBG. Also, the addition of BBG rescued SH-SY5Y cells from cell death induced by amyloid fibrils of lysozyme. Finally, information about the binding sites and interacting forces involved in the BBG-lysozyme interaction was further explored using synchronous fluorescence and molecular docking approaches. Molecular docking results revealed that, apart from the hydrophobic interaction(s), hydrogen bonding, electrostatic interactions, and van der Waal forces may also be involved in the binding interaction.

Modulated transdermal delivery of nonsteroidal anti-inflammatory drug by macroporous poly(vinyl alcohol)-graphene oxide nanocomposite films.

In this study, a facile, economically feasible, and scalable approach to fabricate macroporous poly(vinyl alcohol)-GO (PVA-GO) nanocomposite films with varying filler loadings was demonstrated. The nanocomposite films were prepared using a solvent casting process and employed as a diffusion layer for modulating the transdermal delivery of an anti-inflammatory drug (i.e., ketoprofen). The diffusion membrane was assembled in a three-layer structure with PVA/PVA-GO films between ketoprofen-loaded cellulose and cellulose acetate to mimic skin barrier. Through the incorporation of GO sheets into PVA matrix, the mass diffusion and drug release rate of ketoprofen could be modulated to attain a controlled-release system within period in comparison to that of neat PVA film, which showed more rapid release. It was observed that the dispersion level of GO sheets in the polymer matrix played a crucial role to slow the diffusion rate and drug release, where 3 wt% filler loading gave the slowest rate of release. The results from the present study shed light on the mechanism of and may provide guidelines for modulating drug release rates of NSAID in film-based delivery vehicles for transdermal delivery applications.

Functional gold nanoparticle-based antibacterial agents for nosocomial and antibiotic-resistant bacteria.

AIM: Medical treatments for bacterial-infections have become challenging because of the emergence of antibiotic-resistant bacterial strains. Thus, new therapeutics and antibiotics must be developed. MATERIALS & METHODS: Arginine and tryptophan can target negatively-charged bacteria and penetrate bacterial cell membrane, respectively. Synthetic-peptides containing arginine, tryptophan and cysteine termini, in other words, (DVFLG)2REEW4C and (DVFLG)2REEW2C, as starting materials were mixed with aqueous tetrachloroauric acid to generate peptide-immobilized gold nanoparticles (i.e., [DVFLG]2REEW4C-AuNPs and [DVFLG]2REEW2C-AuNPs) through one-pot reactions. RESULTS & DISCUSSION: The peptide immobilized AuNPs exhibit targeting capacity and antibacterial activity. Furthermore, (DVFLG)2REEW4C-AuNPs immobilized with a higher number of tryptophan molecules possess more effective antibacterial capacity than (DVFLG)2REEW2C-AuNPs. Nevertheless, they are not harmful for animal cells. The feasibility of using the peptide-AuNPs to inhibit the cell growth of bacterium-infected macrophages was demonstrated. CONCLUSION: These results suggested that the proposed antibacterial AuNPs are effective antibacterial agents for Staphylococci, Enterococci and antibiotic-resistant bacterial strains. [Formula: see text].

Targeting cancer initiating cells by promoting cell differentiation and restoring chemosensitivity via dual inactivation of STAT3 and src activity using an active component of antrodia cinnamomea mycelia.

Cancer initiating cells (CICs) represent a subpopulation of cancer cells, which are responsible for tumor growth and resistance to chemotherapy. Herein, we first used a cell-based aldehyde dehydrogenase (ALDH) activity assay to identify that YMGKI-2 (also named as Ergone), an active component purified from Antrodia cinnamomea Mycelia extract (ACME), effectively abrogated the ALDH activity and abolished the CICs in head and neck squamous cell carcinoma cells (HNSCCs). Consequently, YMGKI-2 treatment suppressed self-renewal ability and expression of stemness signature genes (Oct-4 and Nanog) of sphere cells with enriched CICs. Moreover, YMGKI-2 treated sphere cells displayed reduction of CICs properties and promotion of cell differentiation, but not significant cytotoxicity. YMGKI-2 treatment also attenuated the tumorigenicity of HNSCC cells in vivo. Mechanistically, treatment of YMGKI-2 resulted in inactivation of STAT3 and Src. Lastly, combinatorial treatments with YMGKI-2 and standard chemotherapeutic drugs (cisplatin or Fluorouracil) restored the chemosensivity on sphere cells and cisplatin-resistant HNSCC cells. Together, we demonstrate that YMGKI-2 treatment effectively induces differentiation and reduces tumorigenicity of CICs. Further, combined treatment of YMGKI-2 and conventional chemotherapy can overcome chemoresistance. These results suggest that YMGKI-2 treatment may be used to improve future clinical responses in head and neck cancer treatment through targeting CICs.

Transtinib, a potent tyrosine kinase inhibitor inhibits L858R/T790M mutant NSCLC cell lines and xenografts.

Non-small cell lung cancer (NSCLC) patients with activating epidermal growth factor receptor (EGFR) mutations initially respond well to the EGFR tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib. However, clinical efficacy is limited by the development of resistance. In most cases, this resistance is in the form of the T790M mutation. Here, we report the design, synthesis and biochemical evaluation of a novel series of irreversible EGFR tyrosine kinase inhibitors (EGFR-TKIs) that are derived from the anilinoquinazoline scaffold. Guided by molecular modeling, this series of analogs was evolved to target a cysteine residue in the ATP binding site via covalent bond formation and to achieve high levels of anti-tumor activity in cell cultures and in xenografts. The most promising compound 13c ((E) -N - (4 - (4 - (3-fluorobenzyloxy) -3- chlorophenylamino) -7-ethoxyquinazolin-6-yl) -3- ((S) -pyrrolidin-2-yl)acrylamide, which we named Transtinib) displayed strong anti-proliferative activity against the H1975 and A431 cell lines with IC50 values of 34 nM and 62 nM, respectively. In xenograft models, Transtinib significantly decreases tumor size for a prolonged period of time. These results suggest that Transtinib is a potential cancer therapeutic drug lead for the inhibition of mutant EGFR to overcome the development of resistance.

Characteristic expression of major histocompatibility complex and immune privilege genes in human pluripotent stem cells and their derivatives.

Pluripotent stem cells, including human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs), have been regarded as useful sources for cell-based transplantation therapy. However, immunogenicity of the cells remains the major determinant for successful clinical application. We report the examination of several hESC lines (NTU1 and H9), hiPSC lines, and their derivatives (including stem cell-derived hepatocytes) for the expression of major histocompatibility complex (MHC), natural killer (NK) cell receptor (NKp30, NKp44, NKp46) ligand, immune-related genes, human leukocyte antigen (HLA) haplotyping, and the effects in functional mixed lymphocyte reaction (MLR). Flow cytometry showed lower levels (percentages and fluorescence intensities) of MHC class I (MHC-I) molecules, ß2-microglobulin, and HLA-E in undifferentiated stem cells. The levels were increased after cotreatment with interferon-γ and/or in vitro differentiation. Antigen-presenting cell markers (CD11c, CD80, and CD86) and MHC-II (HLA-DP, -DQ, and -DR) remained low throughout the treatments. Recognition of stem cells/derivatives by NK lysis receptors were lower or absent. Activation of responder lymphocytes was significantly lower by undifferentiated stem cells than by allogeneic lymphocytes in MLR, but differentiated NTU1 hESCs induced a cell number-dependent lymphocyte proliferation comparable with that by allogeneic lymphocytes. Interestingly, activation of lymphocytes by differentiated hiPSCs or H9 cells became blunted at higher cell numbers. Real-time reverse transcriptase PCR (RT-PCR) showed significant differential expression of immune privilege genes (TGF-ß2, Arginase 2, Indole 1, GATA3, POMC, VIP, CALCA, CALCB, IL-1RN, CD95L, CR1L, Serpine 1, HMOX1, IL6, LGALS3, HEBP1, THBS1, CD59, and LGALS1) in pluripotent stem cells/derivatives when compared to somatic cells. It was concluded that pluripotent stem cells/derivatives are predicted to be immunogenic, though evidence suggests some level of potential immune privilege. In addition, differential immunogenicity may exist between different pluripotent stem cell lines and their derivatives.

Distinct subpopulations of head and neck cancer cells with different levels of intracellular reactive oxygen species exhibit diverse stemness, proliferation, and chemosensitivity.

Head and neck squamous cell carcinoma (HNSCC) is driven by cancer-initiating cells (CIC), but their maintenance mechanisms are obscure. For hematopoietic stem cells, low levels of intracellular reactive oxygen species (ROS(Low)) is known to help sustain stemness properties. In this report, we evaluated the hypothesis that ROS(Low) character conferred CIC properties in HNSCC. Sphere cultures define CIC in HNSCC cell populations (HN-CIC). We found that ROS(Low) cells in HN-CIC defined in this manner were more numerous than in parental HNSCC cells. Further, ROS(Low) cells frequently coexpressed CIC surface markers such as memGrp78 and Glut3. Exploiting flow cytometry to sort cells on the basis of their ROS level, we found that isolated ROS(Low) cells displayed relatively more CIC properties, including quiescence, chemoresistance, in vitro malignant properties, and tumorigenicity. Pharmacological depletion of ROS modulators in cisplatin-treated HN-CIC reduced CIC properties, enhancing cell differentiation and enhancing cisplatin-induced cell death. Overall, our work defined cell subpopulations in HNSCC on the basis of differential intracellular ROS levels, which associated with stemness and chemoresistance properties. On the basis of our findings, we suggest that strategies to promote intracellular ROS levels may heighten the efficacy of conventional chemotherapy used for HNSCC treatment.

Mesenchymal stem cell insights: prospects in cardiovascular therapy.

Ischemic heart damage usually triggers cardiomyopathological remodeling and fibrosis, thus promoting the development of heart functional failure. Mesenchymal stem cells (MSCs) are a heterogeneous group of cells in culture, with multipotent and hypoimmunogenic characters to aid tissue repair and avoid immune responses, respectively. Numerous experimental findings have proven the feasibility, safety, and efficiency of MSC therapy for cardiac regeneration. Despite that the exact mechanism remains unclear, the therapeutic ability of MSCs to treat ischemia heart diseases has been tested in phase I/II clinical trials. Based on encouraging preliminary findings, MSCs might become a potentially efficacious tool in the therapeutic options available to treat ischemic and nonischemic cardiovascular disorders. The molecular mechanism behind the efficacy of MSCs on promoting engraftment and accelerating the speed of heart functional recovery is still waiting for clarification. It is hypothesized that cardiomyocyte regeneration, paracrine mechanisms for cardiac repair, optimization of the niche for cell survival, and cardiac remodeling by inflammatory control are involved in the interaction between MSCs and the damaged myocardial environment. This review focuses on recent experimental and clinical findings related to cellular cardiomyoplasticity. We focus on MSCs, highlighting their roles in cardiac tissue repair, transdifferentiation, the MSC niche in myocardial tissues, discuss their therapeutic efficacy that has been tested for cardiac therapy, and the current bottleneck of MSC-based cardiac therapies.

Active Component of Antrodia cinnamomea Mycelia Targeting Head and Neck Cancer Initiating Cells through Exaggerated Autophagic Cell Death.

Head and neck squamous cell carcinoma (HNSCC) is a highly lethal cancer. Previously, we identify head and neck cancer initiating cells (HN-CICs), which are highly tumorigenic and resistant to conventional therapy. Therefore, development of drug candidates that effectively target HN-CICs would benefit future head and neck cancer therapy. In this study, we first successfully screened for an active component, named YMGKI-1, from natural products of Antrodia cinnamomea Mycelia (ACM), which can target the stemness properties of HNSCC. Treatment of YMGKI-1 significantly downregulated the aldehyde dehydrogenase (ALDH) activity, one of the characteristics of CIC in HNSCC cells. Additionally, the tumorigenic properties of HNSCC cells were attenuated by YMGKI-1 treatment in vivo. Further, the stemness properties of HN-CICs, which are responsible for the malignancy of HNSCC, were also diminished by YMGKI-1 treatment. Strikingly, YMGKI-1 also effectively suppressed the cell viability of HN-CICs but not normal stem cells. Finally, YMGKI-1 induces the cell death of HN-CICs by dysregulating the exaggerated autophagic signaling pathways. Together, our results indicate that YMGKI-1 successfully lessens stemness properties and tumorigenicity of HN-CICs. These findings provide a new drug candidate from purified components of ACM as an alternative therapy for head and neck cancer in the future.

Mesenchymal stem cell insights: prospects in hematological transplantation.

Adult stem cells have been proven to possess tremendous potential in the treatment of hematological disorders, possibly in transplantation. Mesenchymal stem cells (MSCs) are a heterogeneous group of cells in culture, with hypoimmunogenic character to avoid alloreactive T-cell recognition as well as inhibition of T-cell proliferation. Numerous experimental findings have shown that MSCs also possess the ability to promote engraftment of donor cells and to accelerate the speed of hematological recovery. Despite that the exact mechanism remains unclear, the therapeutic ability of MSCs on hematologic transplantation have been tested in preclinical trials. Based on encouraging preliminary findings, MSCs might become a potentially efficacious tool in the therapeutic options available to treat and cure hematological malignancies and nonmalignant disorders. The molecular mechanisms behind the real efficacy of MSCs on promoting engraftment and accelerating hematological recovery are awaiting clarification. It is hypothesized that direct cell-to-cell contact, paracrine factors, extracellular matrix scaffold, BM homing capability, and endogenous metabolites of immunologic and nonimmunologic elements are involved in the interactions between MSCs and HSCs. This review focuses on recent experimental and clinical findings related to MSCs, highlighting their roles in promoting engraftment, hematopoietic recovery, and GvHD/graft rejection prevention after HSCT, discussing the potential clinical applications of MSC-based treatment strategies in the context of hematological transplantation.

A knock-in Npm1 mutation in mice results in myeloproliferation and implies a perturbation in hematopoietic microenvironment.

Somatic Nucleophosmin (NPM1) mutation frequently occurs in acute myeloid leukemia (AML), but its role in leukemogenesis remains unclear. This study reports the first "conventional" knock-in mouse model of Npm1 mutation, which was achieved by inserting TCTG after nucleotide c.857 (c.854_857dupTCTG) to mimic human mutation without any "humanized" sequence. The resultant mutant peptide differed slightly different from that in humans but exhibited cytoplasmic pulling force. Homozygous (Npm1(c+/c+)) mice showed embryonic lethality before day E8.5, wheras heterozygous (Npm1(wt/c+)) mice appeared healthy at birth and were fertile. Approximately 36% of Npm1(wt/c+) mice developed myeloproliferative disease (MPD) with extramedullary hematopoiesis. Those Npm1(wt/c+) mice that did not develop MPD nevertheless gradually developed monocytosis and showed increased numbers of marrow myeloid precursors. This second group of Npm1(wt/c+) mice also showed compromised cobblestone area formation, suggesting pathology in the hematopoietic niche. Microarray experiments and bioinformatic analysis on mice myeloid precursor cells and 227 human samples revealed the expression of CXCR4/CXCL12-related genes was significantly suppressed in mutant cells from both mice and humans. Thus, our mouse model demonstrated that Npm1 mutation can result in MPD, but is insufficient for leukemogenesis. Perturbation of hematopoietic niche in mutant hematopoietic stem cells (implied by underrepresentation of CXCR4/CXCL12-related genes) may be important in the pathogenesis of NPM1 mutations.

Asymmetric composite membranes from chitosan and tricalcium phosphate useful for guided bone regeneration.

To fulfill the properties of barrier membranes useful for guided bone tissue regeneration in the treatment of periodontitis, in this study a simple process combining lyophilization with preheating treatment to produce asymmetric barrier membranes from biodegradable chitosan (CS) and functional ß-tricalcium phosphate (TCP) was proposed. By preheating TCP/CS (3:10, w/w) in an acetic acid solution at 40°C, a skin layer that could greatly increase the mechanical properties of the membrane was formed. The asymmetric membrane with a skin layer had a modulus value almost 4-times that of the symmetric porous membrane produced only by lyophilization. This is beneficial for maintaining a secluded space for the bone regeneration, as well as to prevent the invasion of other tissues. The subsequent lyophilization at -20°C then gave the rest of material an interconnected pore structure with high porosity (83.9-90.6%) and suitable pore size (50-150 µm) which could promote the permeability and adhesiveness to bone cells, as demonstrated by the in vitro cell-culture of hFOB1.19 osteoblasts. Furthermore, the TCP particles added to CS could further increase the rigidity and the cell attachment and proliferation of hFOB1.19. The TCP/CS asymmetric composite membrane thus has the potential to be used as the barrier membrane for guided bone regeneration.

Cardiac injury protection from mouse bone marrow stromal cells with in utero transplantation followed by secondary postnatal boost.

Limited donor-cell engraftment to the injured tissue restricts therapeutic efficacy of stem cell transplantation. Herein, we proposed an alternative strategy by using in utero transplantation (IUT) to create mixed-chimerism environment in recipients and to facilitate donor-cell engraftment followed by postnatal secondary boost with the same cells. Mouse bone marrow stromal cells (BMSCs) were used as the xenogenic donor cells and given into rat fetus as an early exposure of IUT treatment. The engraftment potential was analyzed for the presence of BMSCs by flow cytometry or PCR in recipient tissues. The function of a second boost of mouse BMSCs, in terms of cardioprotection, was tested by given 1×106 cells to rat IUT hearts with ischemia/reperfusion (IR) injury that was induced by a 45 min of left coronary ligation and released for 72 h. Mouse BMSCs demonstrated an immunosuppressive effect when mixed with mouse or rat lymphocytes. IUT treatment only caused few BMSCs engrafted to fetal (embryonic day 20) and adult (4 weeks after birth) rat organs including heart, but engraftment was increased in hearts of the IUT rats after second boost. This was coincided with attenuation of cardiac injury caused by IR. Interestingly, an up-regulation of CXC chemokine receptor type 4 (CXCR4) was seen when BMSCs were exposed to hypoxia. This indicates that enhanced engraftment of mouse BMSCs to post-ischemic rat hearts possibly is dependent on CXCR4. Moreover, results of flow cytometry demonstrated that the presence of CD34⁺ cells in rat IUT hearts with IR injury was increased. These observations suggest that enhanced engraftment of donor BMSCs to rat IR hearts by CXCR4 may recruit endogenous CD34⁺ cells of recipients which in turn protects heart against IR. This also supports the notion of fetal preconditioning with BMSC enhances the efficiency of progenitor cell-mediated organ protection after a postnatal second boost in xeno-transplantation.

Identification of the nanogold particle-induced endoplasmic reticulum stress by omic techniques and systems biology analysis.

Growth inhibition and apoptotic/necrotic phenotype was observed in nanogold particle (AuNP)-treated human chronic myelogenous leukemia cells. To elucidate the underlying cellular mechanisms, proteomic techniques including two-dimensional electrophoresis/mass spectrometry and protein microarrays were utilized to study the differentially expressed proteome and phosphoproteome, respectively. Systems biology analysis of the proteomic data revealed that unfolded protein-associated endoplasmic reticulum (ER) stress response was the predominant event. Concomitant with transcriptomic analysis using mRNA expression, microarrays show ER stress response in the AuNP-treated cells. The ER stress protein markers' expression assay unveiled AuNPs as an efficient cellular ER stress elicitor. Upon ER stress, cellular responses, including reactive oxygen species increase, mitochondrial cytochrome c release, and mitochondria damage, chronologically occurred in the AuNP-treated cells. Conclusively, this study demonstrates that AuNPs cause cell death through induction of unmanageable ER stress.

HTDP-2, a new synthetic compound, inhibits glutamate release through reduction of voltage-dependent Ca²âº influx in rat cerebral cortex nerve terminals.

AIM: The present study was aimed at investigating the effect of trans-6-(4-chlorobutyl)-5-hydroxy-4-(phenylthio)-1-tosyl-5,6-dihydropyridine-2(1H)-one (HTDP-2), a novel synthetic compound, on the release of endogenous glutamate in rat cerebrocortical nerve terminals (synaptosomes) and exploring the possible mechanism. METHODS: The release of glutamate was evoked by the K⁺ channel blocker 4-aminopyridine (4-AP) and measured by an on-line enzyme-coupled fluorimetric assay. We also used a membrane potential-sensitive dye to assay nerve terminal excitability and depolarization, and a Ca²âº indicator, Fura-2-acetoxymethyl ester, to monitor cytosolic Ca²âº concentrations ([Ca²âº](c)). RESULTS: HTDP-2 inhibited the release of glutamate evoked by 4-AP in a concentration-dependent manner. Inhibition of glutamate release by HTDP-2 was prevented by the chelating intraterminal Ca²âº ions, and by the vesicular transporter inhibitor bafilomycin A1, but was insensitive to the glutamate transporter inhibitor DL-threo-ß-benzyloxyaspartate. HTDP-2 did not alter the resting synaptosomal membrane potential or 4-AP-mediated depolarization whereas it decreased the 4-AP-induced increase in [Ca²âº](c). Furthermore, the inhibitory effect of HTDP-2 on the evoked glutamate release was abolished by the N-, and P/Q-type Ca²âº channel blocker ω-conotoxin MVIIC, but not by the ryanodine receptor blocker dantrolene, or the mitochondrial Na⁺/Ca²âº exchanger blocker CGP37157. CONCLUSION: Based on these results, we suggest that, in rat cerebrocortical nerve terminals, HTDP-2 decreases voltage-dependent Ca²âº channel activity and, in so doing, inhibits the evoked glutamate release.

Protection of bone marrow-derived CD45+/CD34-/lin- stromal cells with immunosuppressant activity against ischemia/reperfusion injury in rats.

Non-hematopoietic CD45+ precursor cells are not known to differentiate into cardiomyocytes. We found that CD45+/CD34-/lin- stromal cells isolated from mouse bone marrow (BMSCs) potentially differentiated into cardiomyocyte-like cells in vitro. Therefore, we hypothesized that the CD45+/CD34-/ lin- BMSCs might protect rat hearts against ischemia/reperfusion (IR) injury following xeno-transplantation. In the present study, BMSCs were isolated by immunoselection and their cellular phenotype and biochemical properties were characterized. The immunological inertness of BMSCs was examined by the allogeneic and xenogeneic mixed lymphocyte reaction (MLR). The potential role of BMSCs for cardioprotection was evaluated by intravenous introduction of 1 x 10(6) cells into rat IR hearts, induced by left coronary ligation for 45 min and released for 72 h. Changes in cardiac contractility and the degree of myocardial injury were assessed. Our findings indicated that BMSCs expressed the muscle-cell marker alpha-actinin after 5-azacytidine treatment. CD45+/CD34-/lin- stromal cells were characterized as mesenchymal progenitor cells based on the expression of Sca-1 and Rex-1. The MLR assay revealed an immunosuppression of BMSCs on mouse and rat lymphocytes. After xeno-transplantation, the BMSCs engrafted into the infarct area and attenuated IR injury. However, increases in intracardial TGF-beta and IFN-gamma contents of IR hearts were not affected by BMSC treatment. Interestingly, ex vivo evidence indicated that CXCR4, SDF-1 and TGFbeta-1 receptors were up-regulated after the cells were exposed to tissue extracts prepared from rat post-IR hearts. In addition, IFN-gamma treatment also markedly increased Sca-1 expression in BMSCs. Mechanistically, these results indicated that CXCR4/SDF-1 and TGF-beta signals potentially enhanced the interaction of BMSCs with the damaged myocardium, and increased IFN-gamma in post-ischemic hearts might cause BMSC to behave more like stem cells in cardioprotection. These data show that CD45+/CD34-/lin- BMSCs possess cardioprotective capacity. Evidently, the accurate production of soluble factors TGF-beta and IFN-gamma in parallel with increased expression of both TGF-beta and Sca-1 receptors may favor BMSCs to achieve a more efficient protective capacity.

Effects of local lidocaine treatment before and after median nerve injury on mechanical hypersensitivity and microglia activation in rat cuneate nucleus.

This study examined the relationship between microglia activation in the cuneate nucleus (CN) and behavioral hypersensitivity after chronic constriction injury (CCI) of the median nerve. We also investigated effects of local lidocaine pre- and post-treatment on microglia activation and development of hypersensitivity in this model. By immunohistochemistry and immunoblotting, little immunoreactivity of OX-42, a microglia activation marker, was detected in the CN of normal rats. As early as 1 day after CCI, there was a significant increase in OX-42 immunoreactivity in the lesion side of CN, which reached a maximum at 14 days. Microinjection of minocycline, a microglia activation inhibitor, into the CN 1 day after CCI attenuated injury-induced behavioral hypersensitivity in a dose-dependent manner. Furthermore, the animals received 1%, 2% or 5% lidocaine 15 min prior to median nerve CCI (pre-treatment), 5h (early post-treatment) or 1 day (late post-treatment) after median nerve CCI. Pre-treatment and early post-treatment with 2% and 5% lidocaine, but not 1% lidocaine, attenuated OX-42 immunoreactivity and behavioral hypersensitivity following median nerve injury. Late post-treatment with 1%, 2%, or 5% lidocaine failed to decrease OX-42 immunoreactivity and mechanical hypersensitivity in CCI rats. In conclusion, median nerve injury-induced microglia activation in the CN modulated development of behavioral hypersensitivity. High-concentration lidocaine was effective in decreasing microglia activation in the CN and in attenuating neuropathic pain sensations at the early stage following nerve injury, when microglia had not yet been activated.