Evaluation of the in vitro and in vivo proinflammatory activities of gold (+) and gold (−) nanoparticles

Objective and design

The aim of this study was to determine potential effects of gold (+) and gold (?) nanoparticles, AuNP(+) and AuNP(?), on neutrophil biology.

Material or subjects

Freshly isolated human neutrophils were used for the in vitro aspects and CD-1 mice were used in the in vivo murine air pouch model of acute neutrophilic inflammation.

Treatment

Human neutrophils were treated with the indicated concentrations of AuNP(+) or AuNP(?) in vitro and mice received 100 or 500 µg/ml AuNP(+) or AuNP(?) into air pouches.

Methods

Cellular uptake of AuNP by neutrophils was confirmed by transmission electron microscopy and the ability of the NP to modulate apoptosis, gelatinase activity, and chemokine production and chemotaxis was determined by cytology, zymography, ELISArray, antibody array, and ELISA and by a micro-chemotaxis chamber, respectively. In vivo, exudates were harvested after 6 h to determine the leukocyte infiltration to detect the production of several cytokines by an antibody array approach and ELISA. One-way analysis of variance was used for statistical analysis.

Results

AuNP possess proinflammatory activities in vitro and induce mainly a neutrophil influx in vivo, albeit at different degrees.

Conclusions

AuNP(+) and AuNP(?) should be added as new candidates into a growing list of NP having proinflammatory activities by themselves.

     

Expression and Localization of α-amylase in the Submandibular and Sublingual Glands of Mice

In the major salivary glands of mice, acinar cells in the parotid gland (PG) are known to be the main site for the production of the digestive enzyme α-amylase, whereas α-amylase production in the submandibular gland (SMG) and sublingual gland (SLG), as well as the cell types responsible for α-amylase production, has been less firmly established. To clarify this issue, we examined the expression and localization of both the mRNA and protein of α-amylase in the major salivary glands of male and female mice by quantitative and histochemical methods. α-amylase mRNA levels were higher in the order of PG, SMG, and SLG. No sexual difference was observed in α-amylase mRNA levels in the PG and SLG, whereas α-amylase mRNA levels in the female SMG were approximately 30% those in the male SMG. Using in situ hybridization and immunohistochemistry, signals for α-amylase mRNA and protein were found to be strongly positive in acinar cells of the PG, serous demilune cells of the SLG, and granular convoluted tubule (GCT) cells of the male SMG, weakly positive in seromucous acinar cells of the male and female SMG, and negative in mucous acinar cells of the SLG. These results clarified that α-amylase is produced mainly by GCT cells and partly by acinar cells in the SMG, whereas it is produced exclusively by serous demilune cells in the SLG of mice.     

Effects of fibrin pad hemostat on the wound healing process in vivo and in vitro

Fibrin Pad is a hemostatic pad designed to control surgical-related bleeding. It consists of a fully absorbable composite matrix scaffold coated with human-derived active biologics that immediately form a fibrin clot upon contact with targeted bleeding surfaces. Studies were conducted to investigate the effect of Fibrin Pad and its biologics-free composite matrix component (Matrix) on the wound healing process in in vitro and in vivo models. Fibrin Pad was evaluated in solid organ, soft tissue defects, and subcutaneous tissues. Immunocompromised rodents were used to avoid xeno-mediated responses. Extracts created from both materials were evaluated for biological activity using in vitro cell culture assays. Neither Fibrin Pad nor Matrix alone showed any inhibition of the wound healing of treated defect sites. An apparent accelerated healing was noted in the soft tissue and subcutaneous tissue defects with Fibrin Pad as compared to Matrix. Both materials showed desirable properties associated with tissue scaffolds. The in vitro study results show that Fibrin Pad extract can induce dose-dependent increases in fibroblast proliferation and migration. These studies confirm that the biologic components of Fibrin Pad can enhance wound healing processes in in vitro assays and fully support wound healing at the site of in vivo application.     

CaSiO₃ microstructure modulating the in vitro and in vivo bioactivity of poly(lactide-co-glycolide) microspheres

Poly(lactide-co-glycolide) (PLGA) microspheres have been used for regenerative medicine due to their ability for drug delivery and generally good biocompatibility, but they lack adequate bioactivity for bone repair application. CaSiO? (CS) has been proposed as a new class of material suitable for bone tissue repair due to its excellent bioactivity. In this study, we set out to incorporate CS into PLGA microspheres to investigate how the phase structure (amorphous and crystal) of CS influences the in vitro and in vivo bioactivity of the composite microspheres, with a view to the application for bone regeneration. X-ray diffraction (XRD), N? adsorption-desorption analysis, and scanning electron microscopy (SEM) were used to analyze the phase structure, surface area/pore volume, and microstructure of amorphous CS (aCS) and crystal CS (cCS), as well as their composite microspheres. The in vitro bioactivity of aCS and cCS-PLGA microspheres was evaluated by investigating their apatite-mineralization ability in simulated body fluids (SBF) and the viability of human bone mesenchymal stem cells (BMSCs). The in vivo bioactivity was investigated by measuring their de novo bone-formation ability. The results showed that the incorporation of both aCS and cCS enhanced the in vitro and in vivo bioactivity of PLGA microspheres. cCS/PLGA microspheres improved better in vitro BMSC viability and de novo bone-formation ability in vivo, compared to aCS/PLGA microspheres. Our study indicates that controlling the phase structure of CS is a promising method to modulate the bioactivity of polymer microsphere system for potential bone tissue regeneration.     

Retinoic acid and α-galactosylceramide differentially regulate B cell activation in vitro and augment antibody production in vivo

All-trans-retinoic acid (RA) promotes the maturation and differentiation of B cells, which are known as a type of professional antigen-presenting cells. We show here that CD1d, a major histocompatibility complex class I-like molecule that presents lipid antigens, is expressed in the mouse spleen B cells and is increased by RA. Thus, we hypothesized that RA and the CD1d ligand, α-galactosylceramide (αGalCer), could interact to promote the differentiation, maturation, and antibody response of antigen-activated B cells. In isolated B cells, αGalCer alone markedly stimulated, and RA further increased B cell proliferation, synergizing with the B cell antigen receptor ligation via anti-μ antibody (P < 0.05). The significantly increased cell proliferation stimulated by αGalCer was abrogated in the B cells of CD1d-null mice. RA alone and combined with αGalCer also promoted B cell differentiation by the enrichment of sIgG1-, CD138-, and PNA/Fas-positive B cells (P < 0.05), suggesting a plasmacytic cell differentiation. In vivo, wild-type mice treated with RA and/or αGalCer during primary immunization with tetanus toxoid produced a higher serum anti-tetanus IgG response and had more bone marrow anti-tetanus antibody-secreting cells as determined by enzyme-linked immunospot assay (P < 0.05) in the secondary response, a finding indicative of heightened long-term memory; however, the increased antibody secretion after αGalCer treatment was abolished in CD1d-null mice. We provide evidence here that RA, together with αGalCer, can effectively regulate B cell proliferation and differentiation, ultimately promoting a more efficient antibody response to protein antigen. The results suggest that the combination of RA and αGalCer could be a useful adjuvant combination in vaccine strategies.     

Molecular properties of the lys1 + gene and the regulation of α-aminoadipate reductase in Schizosaccharomyces pombe

The -aminoadipate pathway for the biosynthesis of lysine is unique to fungi. Molecular properties of the cloned lys1 ⁺ gene and the regulation of the encoded -aminoadipate reductase (AAR) were investigated in the fission yeast Schizosaccharomyces pombe. A 5.2-kb HindIII-EcoRI fragment of S. pombe DNA, containing a functional lys1 ⁺ gene and a promoter, was subcloned to make the 10.7-kb plasmid pLYS1H. A nested 1.778-kb HindIII-EcoRI DNA fragment that complemented the lys1-131 mutant phenotype was sequenced from the plasmid pLYS1D, and shown to contain an open reading frame (ORF) of 470 amino acids, preceded by putative POLII promoter elements (TATA and CCAAT box elements, and two potential yeast GCN4-binding motifs) within 368 bp upstream of the start codon. This ORF shared with the corresponding region of the isofunctional AAR of Saccharomyces cerevisiae 49% amino-acid identity (62% similarity) overall, within which were smaller regions of marked sequence conservation. One such region coincided (95% identity) with a putative AMP-binding domain motif identified in the AAR of S. cerevisiae. In wild-type S. pombe, AAR activity from cells grown in lysine-supplemented minimal or YEPD media was less than the activity of cells grown in minimal mediu. The AAR of S. pombe was more sensitive to feedback inhibition by lysine in vitro than the AAR of S. cerevisiae. These results show the effects of extensive evolutionary divergence on the structure and expression of a pivotal enzyme in the -aminoadipate pathway. Presumably, delineated regions of strong sequence conservation correspond to discrete domains essential to AAR function.     

Expression of E-cadherin, α-catenin, and β-catenin in tubulolobular carcinoma of the breast

Tubulolobular carcinoma (TLC) of the breast is a rare subtype of breast carcinoma categorized by Fisher et al. (Hum Pathol 8:679–683, 1977) as a tubular variant of lobular carcinoma. E-cadherin is a transmembrane glycoprotein, and complete loss of E-cadherin expression has been observed in invasive lobular carcinoma. Ductal carcinoma retains at least some expression of E-cadherin. Moreover, the adhesive function of E-cadherin is dependent on the integrity of the catenin components, which link E-cadherin to the actin filaments. In order to achieve improved categorization of TLC, we decided to investigate both E-cadherin and the catenins in TLCs and invasive lobular carcinomas. We reviewed all 1,430 cases of primary breast carcinoma that were surgically resected at Saitama Medical Center, Saitama Medical School, and at Saitama Red Cross Hospital between 1990 and 2005. Among these, 16 cases of TLC were reported retrospectively. The results were compared with those of 20 cases of invasive lobular carcinomas that were included as controls. Tumor tissue was immunostained for E-cadherin, α-catenin, and β-catenin. The presence of immunoreactivity in the TLC was seen in 12 (75%) cases for E-cadherin, in 8 (50%) cases for α-catenin, and in 10 (62.5%) cases for β-catenin. However, plasma-membrane-associated staining for E-cadherin, α-catenin, and β-catenin was completely absent in invasive lobular carcinomas. These results suggest the possibility that TLCs are not a variant of lobular carcinoma, but rather ductal carcinomas with a lobular growth pattern.     

Expression and regulation of the ΔN and TAp63 isoforms in salivary gland tumorigenesis clinical and experimental findings

The TP63 gene, a TP53 homologue, encodes for two main isoforms by different promoters: one retains (TA) and the other lacks (ΔN) the transactivation domain. p63 plays a critical role in the maintenance of basal and myoepithelial cells in ectodermally derived tissues and is implicated in tumorigenesis of several neoplastic entities. However, the biological and regulatory roles of these isoforms in salivary gland tumorigenesis remain unknown. Our results show a reciprocal expression between TA and ΔN isoforms in both benign and malignant salivary tumors. The most dominantly expressed were the ΔN isoforms, whereas the TA isoforms showed generally low levels of expression, except in a few tumors. High ΔNp63 expression characterized tumors with aggressive behavior, whereas tumors with high TAp63 expression were significantly smaller and less aggressive. In salivary gland cells, high expression of ΔNp63 led to enhanced cell migration and invasion and suppression of cell senescence independent of TAp63 and/or TP53 gene status. We conclude the following: i) overexpression of ΔNp63 contributes to salivary tumorigenesis, ii) ΔNp63 plays a dominant negative effect on the TA isoform in the modulation of cell migration and invasion, and iii) the ΔN isoform plays an oncogenic role and may represent an attractive target for therapeutic intervention in patients with salivary carcinomas.     

Diverse roles of TGF-β receptor II in renal fibrosis and inflammation in vivo and in vitro

TGF-β1 binds receptor II (TβRII) to exert its biological activities but its functional importance in kidney diseases remains largely unclear. In the present study, we hypothesized that TβRII may function to initiate the downstream TGF-β signalling and determine the diverse role of TGF-β1 in kidney injury. The hypothesis was examined in a model of unilateral ureteral obstructive (UUO) nephropathy and in kidney fibroblasts and tubular epithelial cells in which the TβRII was deleted conditionally. We found that disruption of TβRII inhibited severe tubulointerstitial fibrosis in the UUO kidney, which was associated with the impairment of TGF-β/Smad3 signalling, but not with the ERK/p38 MAP kinase pathway. In contrast, deletion of TβRII enhanced NF-κB signalling and renal inflammation including up-regulation of Il-1β and Tnfα in the UUO kidney. Similarly, in vitro disruption of TβRII from kidney fibroblasts or tubular epithelial cells inhibited TGF-β1-induced Smad signalling and fibrosis but impaired the anti-inflammatory effect of TGF-β1 on IL-1β-stimulated NF-κB activation and pro-inflammatory cytokine expression. In conclusion, TβRII plays an important but diverse role in regulating renal fibrosis and inflammation. Impaired TGF-β/Smad3, but not the non-canonical TGF-β signalling pathway, may be a key mechanism by which disruption of TβRII protects against renal fibrosis. In addition, deletion of TβRII also enhances NF-κB signalling along with up-regulation of renal pro-inflammatory cytokines, which may be associated with the impairment of anti-inflammatory properties of TGF-β1.     

An increase in apoptosis and reduction in αB-crystallin expression levels in the lens underlie the cataractogenesis of Morioka cataract (MCT) mice

We examined the morphological changes in fibers, localization of apoptotic cells, and protein expression of αB-crystallin in the lens of Morioka cataract (MCT) mice, a novel cataract model. Using a scanning electron microscope, swollen lens fibers and enlarged spaces between lens fibers were observed in the lens of 3-week-old MCT mice. At 2 weeks of age (before cataract), the single-strand DNA (ssDNA)-positive (indicating apoptosis) cell ratio of the lens epithelium was significantly higher in MCT than in wild-type ddY mice. At 2 and 4 weeks of age, αB-crystallin protein expression of the lens in MCT mice was significantly lower than that in wild-type ddY mice. These findings suggest that increase in apoptosis and reduction in αBcrystallin level are involved in the cataractogenesis of MCT mice.     

The prion-like spreading of α-synuclein: From in vitro to in vivo models of Parkinson’s disease

Parkinson’s disease (PD) is the second most common neurodegenerative disorder after Alzheimer’s disease. PD is characterized by the loss of dopaminergic neurons, primarily in brain regions that control motor functions, thereby leading to motor impairments in the patients. Pathological aggregated forms of the synaptic protein, α-synuclein (α-syn), are involved in the generation and progression of PD. In PD brains, α-syn accumulates inside neurons and propagates from cell-to-cell in a prion-like manner. In this review, we discuss the in vitro and in vivo models used to study the prion-like properties of α-syn and related findings. In particular, we focus on the different mechanisms of α-syn spreading, which could be relevant for the development of alternative therapeutic approaches for PD treatment.     

On the in vitro and in vivo degradation performance and biological response of new biodegradable Mg–Y–Zn alloys

A design strategy deployed in developing new biodegradable Mg–Y–Zn alloys is summarized and the key factors influencing their suitability for medical applications are described. The Mg–Y–Zn alloys reveal microstructural features and mechanical characteristics expected to be appropriate for vascular intervention applications. The focus of this article lies in the evaluation of the degradation performance and biological response of the alloys with respect to their potential as implant materials (stents). The degradation characteristics analyzed by immersion testing and electrochemical impedance spectroscopy in simulated physiological media reveal slow and homogeneous degradation. In vitro cell tests using human umbilical vein endothelial cells indicate good cytocompatibility on the basis of the alloys’ eluates (extracts). Animal studies carried out with pigs on Mg–2Y–1Zn (in wt.%) reveal an auspicious in vivo performance. Evaluation of preparations derived from implants in various types of tissues indicates homogeneous degradation and only limited gas formation during in vivo testing. The characteristics of the tissue reactions indicate good biocompatibility. The new Mg–Y–Zn alloys show an interesting combination of preferred microstructural, mechanical, electrochemical and biological properties, which make them very promising for degradable implant applications.     

In vitro,in vivo and numerical assessment of the working principle of the truCCOMS™ continuous cardiac output catheter system

The truCCOMS? cardiac output monitor system provides a continuous and instantaneous measurement of cardiac output, derived from the amount of energy required for heating a filament to maintain a fixed 2 °C blood temperature difference between two thermistors located distally on a pulmonary artery catheter. Clinical studies, however, reported relatively poor accuracy of the cardiac output estimation, possibly due to linearly assumed power–cardiac output relationship used for calibration of the catheters. We experimentally studied the shape of the truCCOMS? calibration relationship (i) in a hydraulic bench model of the right heart and (ii) in vivo intact animal model. The results showed a nonlinear relationship between the power input into the heating element and the cardiac output; which could satisfactorily be described with an exponential relationship. Comparison of the performance of the same catheters in vitro and in vivo showed that the in vitro determined calibration relationship should not be used for in vivo measurements. Finally, we also simulated the working principle of the catheter using a simplified numerical model of the blood flow and heat transfer around the catheter. The computed results also suggested a pronounced nonlinear relationship between power and cardiac output in pulsatile conditions. We conclude that the observed over- and underestimation of high- and low flows, respectively, by the current truCCOMS? system is likely to arise from its linear calibration relationship. An appropriate calibration scheme accounting for the intrinsic nonlinear power–cardiac output relationship and the difference between in vitro and in vivo conditions should improve the clinical performance of the system.