Research advances of nanomaterials for the acceleration of fracture healing

The bone fracture cases have been increasing yearly, accompanied by the increased number of patients experiencing non-union or delayed union after their bone fracture. Although clinical materials facilitate fracture healing (e.g., metallic and composite materials), they cannot fulfill the requirements due to the slow degradation rate, limited osteogenic activity, inadequate osseointegration ability, and suboptimal mechanical properties. Since early 2000, nanomaterials successfully mimic the nanoscale features of bones and offer unique properties, receiving extensive attention. This paper reviews the achievements of nanomaterials in treating bone fracture (e.g., the intrinsic properties of nanomaterials, nanomaterials for bone defect filling, and nanoscale drug delivery systems in treating fracture delayed union). Furthermore, we discuss the perspectives on the challenges and future directions of developing nanomaterials to accelerate fracture healing.

Facile Fabrication of Lignin-Cellulose Green Nanogels

There has been increasing exploration of the development and production of biodegradable polymers in response to issues with petrol-based polymers and their impact on the environment. Here we report a new approach to synthesize a natural nanogel from lignin and nanocellulose. First lignin nanobeads were synthesized by a solvent-shifting method, which showed a spherical shape with a diameter of 159.7 nm. Then the lignin nanobeads were incorporated into a nanocellulose network to form the lignin/cellulose nanogels. The nanocellulose fibrils (CNF-C) nanogels reveal a higher storage modulus than the nanocellulose crystal (CNC-C) ones due to the denser network with self-entanglement of longer cellulose chains. The presence of lignin nanobeads in the nanogels helped to increase the viscoelasticity of the nanogels. This work highlights that the new kinds of green nanogels could be potentially utilized in a variety of biomedical applications such as drug delivery and wound dressing.

Nonvolatile modulation of luminescence in perovskite oxide thin films by ferroelectric gating

Nonvolatile and giant modulation of luminescence can be realized by the ferroelectric gating effect in a Ga³⁺/Pr³⁺ co-doped BaTiO₃ ultra-thin film epitaxially grown on a [Pb(Mg_1/3Nb_2/3)O₃]_0.7-[PbTiO₃]_0.3 single-crystallized substrate. The change behavior of the emission intensity matches that of the ferroelectric polarization hysteresis loop with a giant enhancement of over 13 times with negative polarization orientation. The interaction of O^2- at the O2p orbital in the valence band and Pr³⁺ with injected holes by the ferroelectric gating effect promotes the formation of excited state O^-, Pr⁴⁺, or Pr^3+q. This ferroelectric gating method can promote the development of controllable photo-, electroluminescent, and other optoelectronic devices for display, sensing, communication, and so on.

[The application of 3D reconstruction in investigating the frontal sinus drainage pathway based on computer tomography data]

Objective:The aim of this study is to explore the value of 3D reconstruction technology based on computer tomography data in understanding the frontal sinus drainage pathway. Method:Three-dimensional reconstruction of DICOM data from 100 cases of sinus CT was performed by using Mimics 19.0 software. The 3D models were used to study types, the relative locations of frontal sinus and recess cells as well as the influence of the frontal sinus drainage pathway. Result:The 3D model of frontal sinus, frontal recess cells and frontal sinus drainage pathway were reconstructed successfully. Among them, the incidence of nasal cavity was 95.5% (191/200), nasal cavity was 31.5% (63/200), nasal cavity on the frontal air room was 24.5% (49/200) supra bulla cells were 54% (108/200), supra bulla frontal cells were 14.5% (29/200), supraorbital ethmoid cells were 20.5% (41/200), and the rate of frontal septal cells were 4% (8/200). It visually demonstrated the relationship between the frontal recess and the frontal sinus drainage channel. Conclusion:The 3D reconstruction technology based on computer tomography data not only helps us to understand the anatomy of the frontal sinus, the relative position of the frontal crypt and the effect on the frontal sinus drainage channel, but also provides a new method for preoperative planning and intraoperative guidance to endoscopic frontal sinus surgery.

Unprecedented Acid-Promoted Polymerization and Gelation of Acrylamide: A Serendipitous Discovery

Dilute acid polymerizes degassed, aqueous acrylamide with concomitant gelation, without the need for added free radical initiator or cross-linking agent. This reaction is accelerated by sonication or UV irradiation, but inhibited by adventitious oxygen or the addition of a free radical inhibitor, suggesting an acid-accelerated free radical process. The resulting hydrogels are thixotropic in nature and partially disrupted by the addition of chaotropic agents, indicating the importance of hydrogen bonding to the 3D network. This discovery was made while trying to prepare pectin-polyacrylamide hydrogels. We observed that pectin initiated the gelation of acrylamide, but only if the aqueous pectin samples had a pH lower than ca. 5.

Poly(carbonate urethane)-Based Thermogels with Enhanced Drug Release Efficacy for Chemotherapeutic Applications

In this study, we report the synthesis and characterisation of a thermogelling poly(carbonate urethane) system comprising poly(ethylene glycol) (PEG), poly(propylene glycol) (PPG) and poly(polytetrahydrofuran carbonate) (PTHF carbonate). The incorporation of PTHF carbonate allowed for the control of the lower critical solution temperature (LCST) and decreased critical gelation concentration (CGC) of the thermogels significantly. In addition, the as-prepared thermogels displayed low toxicity against HepG2, L02 and HEK293T cells. Drug release studies were carried out using doxorubicin (Dox). Studies conducted using nude mice models with hepatocellular carcinoma revealed that the Dox-loaded poly(PEG/PPG/PTHF carbonate urethane) thermogels showed excellent in vivo anti-tumour performance and effectively inhibited tumour growth in the tested model.

Long-Term Real-Time In Vivo Drug Release Monitoring with AIE Thermogelling Polymer

A new drug concentration meter is developed. In vivo drug release can be monitored precisely via a self-indicating drug delivery system consisting of a new aggregation-induced emission thermoresponsive hydrogel. By taking the advantage of a self-indicating system, one can easily detect the depletion of drugs, and reinject to maintain a dosage in the optimal therapeutic window.

A new light triggered approach to develop a micro porous tough hydrogel

A porous tough hydrogel (alginate–polyacrylamide) is successfully synthesized using a photo-gelling polymer as a templating agent.

Modification of Thermal and Mechanical Properties of PEG-PPG-PEG Copolymer (F127) with MA-POSS

Pluronic F127 exhibits thermogelling behaviour at 20⁻30 °C via a micelle packing mechanism. Disruption of the micelle packing increases the sol-gel temperature, but results in the decrease of modulus. Herein, we reported a method to modify F127 with polyhedral oligosilsesquioxane (POSS) to impart a higher gelling temperature without yielding the property and strength of the thermogel. The thermal degradation temperature was enhanced to 15 °C after POSS incorporation and the gelling temperature shifted 10 °C higher, without sacrificing the modulus of the gel. Rheological studies supported the claim that the gel property was reinforced after POSS incorporation. F127-POSS copolymer matrix stored more energy from POSS reinforcement, which saw larger Lissajous curve areas before the collapse of the microstructure for the same amount of stress applied. These results indicated that modification with POSS would raise the sol-gel transition temperature without sacrificing the modulus of the gel.

New Linear and Star-Shaped Thermogelling Poly([R]-3-hydroxybutyrate) Copolymers

The synthesis of multi-arm poly([R]-3-hydroxybutyrate) (PHB)-based triblock copolymers (poly([R]-3-hydroxybutyrate)-b-poly(N-isopropylacrylamide)-b-[[poly(methyl ether methacrylate)-g-poly(ethylene glycol)]-co-[poly(methacrylate)-g-poly(propylene glycol)]], PHB-b-PNIPAAM-b-(PPEGMEMA-co-PPPGMA), and their subsequent self-assembly into thermo-responsive hydrogels is described. Atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAM) followed by poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and poly(propylene glycol) methacrylate (PPGMA) was achieved from bromoesterified multi-arm PHB macroinitiators. The composition of the resulting copolymers was investigated by (1) H and (13) C J-MOD NMR spectroscopy as well as size-exclusion chromatography (SEC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The copolymers featuring different architectures and distinct hydrophilic/hydrophobic contents were found to self-assemble into thermo-responsive gels in aqueous solution. Rheological studies indicated that the linear one-arm PHB-based copolymer tend to form a micellar solution, whereas the two- and four-arm PHB-based copolymers afforded gels with enhanced mechanical properties and solid-like behavior. These investigations are the first to correlate the gelation properties to the arm number of a PHB-based copolymer. All copolymers revealed a double thermo-responsive behavior due to the NIPAAM and PPGMA blocks, thus allowing first the copolymer self-assembly at room temperature, and then the delivery of a drug at body temperature (37 °C). The non-significant toxic response of the gels, as assessed by the cell viability of the CCD-112CoN human fibroblast cell line with different concentrations of the triblock copolymers ranging from 0.03 to 1 mg mL(-1) , suggest that these PHB-based thermo-responsive gels are promising candidate biomaterials for drug-delivery applications.

Correlation between protein 4.1R and the progression of heart failure in vivo

We aimed to assess the protein 4.1R (4.1R) expression of the membrane skeleton in cardiomyocytes and to determine the potential role of 4.1R in the pathogenesis of heart failure (HF). Forty-two male mice were randomly divided into two groups: an HF group (N = 22) and control group (N = 20). The HF model was established by abdominal subcutaneous injection of 5 mg⋅kg(-1)⋅day(-1) isopropyl adrenaline to the mice for 14 days. Electrocardiography was carried out and cardiac function was assessed by ultrasonic cardiogram. The left ventricular weight index (LVMI) was measured after mice were sacrificed, and the pathological changes of the heart were observed by hematoxylin and eosin staining. The expression of 4.1R in cardiomyocytes was analyzed by immunohistochemistry, immunofluorescence, and reverse transcription polymerase chain reaction. The echocardiographs showed that the left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD) were significantly higher in the HF group than in the controls (P < 0.05), while the left ventricle shortening fraction was remarkably lower than that in the controls (P < 0.05). Electrocardiography showed faster heart rates in the HF group than in the control group (P < 0.05). Both the LVMI and the myocardial tissue pathological score were significantly higher (P < 0.01) in the HF group than in the controls. 4.1R localized mostly to the plasma membrane and was distributed discretely in the cytosol of myocardial cells. The proportion of 4.1R-positive cells was significantly higher in the HF group (P < 0.01) than in the controls, which was confirmed by the positive mRNA expression of 4.1R. 4.1R localized mostly to the plasma membrane of myocardial cells and was upregulated with the progression of HF. This suggests that 4.1R may be associated with HF progression and therefore 4.1R represents a promising therapeutic target in HF.

Emerging Supramolecular Therapeutic Carriers Based on Host-Guest Interactions

Recent advances in host-guest chemistry have significantly influenced the construction of supramolecular soft biomaterials. The highly selective and non-covalent interactions provide vast possibilities of manipulating supramolecular self-assemblies at the molecular level, allowing a rational design to control the sizes and morphologies of the resultant objects as carrier vehicles in a delivery system. In this Focus Review, the most recent developments of supramolecular self-assemblies through host-guest inclusion, including nanoparticles, micelles, vesicles, hydrogels, and various stimuli-responsive morphology transition materials are presented. These sophisticated materials with diverse functions, oriented towards therapeutic agent delivery, are further summarized into several active domains in the areas of drug delivery, gene delivery, co-delivery and site-specific targeting deliveries. Finally, the possible strategies for future design of multifunctional delivery carriers by combining host-guest chemistry with biological interface science are proposed.

Nanomaterial mediated optogenetics: opportunities and challenges

This review elaborates on the possible applications of nanomaterials in optogenetics and analyses the benefits of nanomaterial-mediated optogenetics.

Utilising inorganic nanocarriers for gene delivery

The delivery of genetic materials into cells to elicit cellular response has been extensively studied by biomaterials scientists globally.

Cationic Micelles Based on Polyhedral Oligomeric Silsesquioxanes for Enhanced Gene Transfection

The synthesis and gene transfection efficiency of a series of amphiphilic copolymers, poly(2-(dimethylamino)ethyl methacrylate)-poly (methacrylate isobutyl polyhedral oligomeric silsesquioxane) (PDMAEMA-POSS) copolymers are reported. The hydrophobic POSS interior allows a cell-sensitizing drug such as paclitaxel to be incorporated, whereas the cationic and hydrophilic PDMAEMA corona allows the complexation of anionic DNA to form a nano-sized polyplex. These drug-encapsulated copolymers display excellent gene transfection efficiency compared with polyethylenimine or PDMAEMA homopolymers.

Integration of p-type β-In2S3 thin films on III-nitride heterostructures for multiple functional applications

We report conversion of n-type InN thin films on III-nitride heterostructures to p-type β-In₂S₃ by postgrowth heat treatments in a sulfur-vapor environment and address their photoelectrical and photocatalytic properties for functional integrations.

Prosthesis replacement in Mason III radial head fractures: A meta-analysis

INTRODUCTION

This present study was to evaluate the clinical efficacy of prosthesis replacement (PR) for patients with Mason III radial head fractures (RHF) compared with open reduction and internal fixation (ORIF).

METHODS

We retrieved the relevant trials up to September 2013 from several public databases, mainly including PubMed, Embase, Springer, Elsevier Science Direct, Cochrane Library, Google scholar, CNKI and Wanfang database. Weighted mean difference (WMD) or odds ratio (OR) and their 95% confidence intervals (CI) were calculated to compare the clinical outcomes between PR and ORIF.

RESULTS

A total of 9 studies including 365 patients with Mason III RHF (169 patients treated with PR and 196 patients treated with ORIF) were reanalyzed in the meta-analysis. The results showed that the patients with Mason III RHF receiving PR, compared with the ORIF ones, had a significantly higher percentage of postoperative excellent and good rate (OR=3.48, 95% CI=1.98 to 6.11, P<0.0001), better Broberg and Morrey elbow scores (WMD=9.79, 95% CI=4.22 to 15.36, P=0.0006) and significantly lower postoperative complications (OR=0.33, 95% CI=0.16 to 0.69, P=0.003).

CONCLUSIONS

Although the results of this study supported the use of PR in the treatment of Mason III RHF in Chinese population with short-term outcomes, the evidences are of low quality and further studies were required for confirming these results in the longer term on other populations.

LEVEL OF EVIDENCE

Level III. Low power meta-analysis.

Multi-functional fluorescent carbon dots with antibacterial and gene delivery properties

Dual-functionality carbon dots with both anti-microbial and gene transfection abilities were developed and their properties elaborated in this paper.

Genetic association of IL-21 polymorphisms with dilated cardiomyopathy in a Han Chinese population

BACKGROUND

Autoimmune abnormalities appear to be major predisposing factors for dilated cardiomyopathy (DCM). Interleukin-21 (IL-21) gene polymorphisms have been previously found to be associated with autoimmune diseases. This study aimed to assess the role of IL-21 in DCM in a Han Chinese population.

PATIENTS AND METHODS

A total of 364 independent DCM patients and 384 unrelated healthy controls were recruited for this case-control association study. rs2055979 and rs12508721 were genotyped by PCR-RFLP. IL-21 plasma levels in samples from DCM and control individuals were evaluated by ELISA. The association between the SNPs and overall survival (OS) was evaluated by Kaplan-Meier analysis. Hazard ratios and 95 % confidence intervals (CIs) were assessed in a Cox regression analysis with adjustment for sex and age.

RESULTS

The T allele frequencies of both SNPs were higher in DCM patients than in controls (p < 0.001). The genotypic frequencies of rs2055979 G > T and rs12508721 C > T were associated with DCM in the codominant, dominant, and recessive models (p < 0.05). IL-21 plasma levels in patients were higher than those of the control subjects (p = 0.009). The TT genotypes of both SNPs were associated with significantly higher plasma levels (prs2055979 = 0.03, prs12508721 < 0.001). Kaplan-Meier analysis showed that the genotypic frequencies of both SNPs were associated with OS in the dominant and the recessive models (p < 0.001). The TT genotypes of both SNPs were associated with the worst OS (p < 0.001).

CONCLUSION

Our findings suggest that theIL-21 gene plays an important role in susceptibility to DCM as well as in the clinical outcome of this ailment in the Han Chinese population.

Effect of Malonic Acid/Calcium Stearate Bicomponent Nucleator on the β-Crystalline Formation in Isotactic Poly(propylene)

The effect of a new bicomponent β-nucleator composed of malonic acid (MA) and calcium stearate (CaSt) on the formation of the β-crystalline form in isotactic polypropylene (iPP) has been investigated. It has been found that the relative content of the β-crystalline form (k value) of iPP notably increases with the addition of the MA/CaSt mixture, and it attains a maximum value of 0.94 at 0.15% MA/0.30% CaSt. For iPP nucleated with the bicomponent nucleator, the spherulitic size decreases continuously with increasing CaSt dosage. FTIR analysis has shown that an “in situ” reaction may occur between MA and CaSt during melt blending, yielding an effective β-nucleator (calcium malonate, CaMt). The β-nucleation efficiency of an MA/CaSt mixture is higher than that of CaMt itself; this may be ascribed to greater dispersion of the “in situ” produced CaMt in the iPP matrix through the assistance of the CaSt residue and the stearic acid.

Involvement of RB kinases and phosphatases in life and death decisions

Previously we found that retinoblastoma protein (RB) became dephosphorylated in an early stage of DNA damage-induced, p53-independent apoptosis. Here, we report that both RB dephosphorylation and apoptosis are regulated by relative levels of RB kinases (cyclin-dependent kinases, or cdks) and phosphatases. Treatment of human Jurkat T cells with roscovitine, a potent and selective synthetic inhibitor of several cdks, rapidly induced RB dephosphorylation, which was followed by induction of apoptosis-associated internucleosomal DNA fragmentation. The roscovitine treatment did not increase levels of the endogenous cdk inhibitor proteins p16(Ink4a), p27(kip1) and p21(Waf1), supporting the idea that the observed RB dephosphorylation was due to a direct inhibition of cdk activities by roscovitine. Treatment with a protein kinase C inhibitor (sphingosine or staurosporine), which leads to suppression of several cdk kinase activities, also induced cellular RB dephosphorylation and apoptosis. Finally, roscovitine- or sphingosine-induced RB dephosphorylation was blocked by a specific inhibitor of protein-serine/threonine phosphatases (calyculin A or okadaic acid). Therefore, RB phosphorylation status and cellular fate are regulated by the ratio of RB kinases to RB phosphatases.

Tuning the autophagy-inducing activity of lanthanide-based nanocrystals through specific surface-coating peptides

The induction of autophagy on exposure of cells to a variety of nanoparticles represents both a safety concern and an application niche for engineered nanomaterials. Here, we show that a short synthetic peptide, RE-1, identified by means of phage display, binds to lanthanide (LN) oxide and upconversion nanocrystals (UCN), forms a stable coating layer on the nanoparticles' surface, and effectively abrogates their autophagy-inducing activity. Furthermore, RE-1 peptide variants exhibit a differentially reduced binding capability, and correspondingly, a varied ability to reduce the autophagic response. We also show that the addition of an arginine-glycine-aspartic acid (RGD) motif to RE-1 enhances autophagy for LN UCN through the interaction with integrins. RE-1 and its variants provide a versatile tool for tuning material-cell interactions to achieve the desired level of autophagy, and may prove useful for the various diagnostic and therapeutic applications of LN-based nanomaterials and nanodevices.

Tuning of the structure and emission spectra of upconversion nanocrystals by alkali ion doping

Recently, lanthanide based nanocrystals with upconversion fluorescence emission have attracted a lot of interest and the nanocrystals have been used for bioimaging, biodetection, and therapeutic applications. Use of the nanocrystals for multiplexed detection has also been explored; however, nanocrystals with multicolor emission are required. Some efforts have been made to tune the emission spectra of the nanocrystals based on manipulation of upconverting lanthanide ions doped in the crystals or creation of core/shell structures. In this work, alkali ions with an ionic radius slightly larger or smaller than Na such as Li and K were doped into NaYF(4):Yb,Er nanocrystals and their effect on the crystal structure and subsequently the upconversion emission spectra were studied. It was found that the phase transition occurs in the nanocrystals when a different amount of Li and K was doped. Furthermore, the intensity ratios between the blue, green, and red emission peaks changed accordingly, and make it possible to tune the upconversion fluorescence of the nanocrystals by Li and K doping.

Molecular dynamics simulation of the interfacial structure of [C(n)mim][PF6] adsorbed on a graphite surface: effects of temperature and alkyl chain length

The structures and diffusion behaviors of a series of ionic liquids [C(n)mim][PF(6)] (n = 1, 4, 8 and 12) on a graphite surface have been investigated by means of molecular dynamics simulation. It was found that three or four ordering layers of ionic liquids were formed near the graphite surface, and this layering structure was stable over the temperature range investigated. At the liquid/vacuum interface, the ionic liquid with a butyl chain had a monolayer ordering surface, while [C(8)mim][PF(6)] and [C(12)mim][PF(6)] exhibited a bilayer ordering with a polar domain sandwiched between two orientational nonpolar domains. More impressively, the simulated results showed that for the ionic liquids with alkyl chains longer than C(4), the adjacent alkyl chains in the whole film tended to be parallel to each other, with the imidazolium rings packed closely together. This indicated that the ionic liquids have a better regulated short-range structure than was previously expected. It was also found that both in the bottom layer and in the bulk region, the diffusion of the alkyl chains was much faster than that of the polar groups. However, as the alkyl chain length increased, the charge delocalization in the cation and the enhanced van der Waals interaction between the nonpolar groups contributed by reducing this difference in the diffusivity of major groups.

Structural features of the 5’ flanking region of the Yak (Bos grunniens) growth hormone receptor (GHR) gene (Brief Report)

Abstract. Yak (Bos grunniens) is a species of the Bovidae family living on the Qinghai-Tibetan Plateau and its adjacent territories at altitudes from 2 000–5 000 m (LUO et al. 2005, MA et al. 2009). As a multi-purpose domestic animal, yaks are indispensable to the local animal husbandry development because it can provide life necessities such as meat, milk, fur, velour manufacturing, transportation and manure for fuel to the local herdsmen. There are twelve yak populations numbered around 13.3 million in China and the Bazhou yak is one of Chinese yak populations (WIENER et al. 2003). The Growth Hormone Receptor (GHR) gene was identified as a candidate gene affecting key quantitative traits, like growth, milk yield and composition in livestock. At present, only investigations were carried out on the genetic variation in Exon-8, Intron-8 and Exon-10 of the yak GHR gene (VARVIO et al. 2008), no other information on the yak GHR gene is available. The purposes of this study were to – analyze the structural features of the 5’ flanking region of the yak GHR gene – compare the 5’ flanking region of yak GHR gene with that of other species of the Bovidae family and – construct the phylogenetic tree to indicate the evolutionary relationship among them.

An inverse relation between the expression of tumor necrosis factor alpha (TNF-alpha) and TNF-alpha receptor in human endometrium

PROBLEM

To determine whether the expression of tumor necrosis factor (TNF-alpha) correlates with TNF-alpha receptor expression in human endometrium.

METHOD OF STUDY

A multiprimer synthetic cDNA standard template containing complimentary sequences for several cytokines including TNF-alpha and TNF-alpha receptor type 2 was constructed and used in quantitative reverse transcription polymerase chain reaction (Q-RT-PCR).

RESULTS

Endometrium from proliferative phase of the menstrual cycle expresses higher levels of TNF-alpha mRNA (2.35 +/- 0.2 x 10(5) copies/microg of total cellular RNA) than secretory phase ([1.3 +/- 0.08 x 10(5) copies] P < 0.05), with a significant reduction during menses (1.2 +/- 0.1 x 10(4) copies) and postmenopausal period (8.1 +/- 1.6 x 10(4) copies [P < 0.05]). In contrast, TNF-alpha type 1 receptor mRNA expression was higher in endometrium from the secretory phase (6.6 +/- 0.6 x 10(7) copies) compared to the menses (5.1 +/- 0.5 x 10(6) copies), proliferative phase (1.9 +/- 0.1 x 10(6) copies) and postmenopausal period (5.8 +/- 0.7 x 10(4) copies [P < 0.05]). Comparatively, TNF-alpha receptor type 2 is expressed 10 to 100 fold higher in the endometrium than TNF-alpha (P < 0.05).

CONCLUSION

The data confirm that human endometrium expresses TNF-alpha; and provide the first evidence that TNF-alpha expression is inversely related to TNF-alpha type 1 receptor expression during the menstrual cycle. Such an inverse relation between TNF-alpha and TNF-alpha receptor expression may provide a regulatory mechanism necessary to overcome the detrimental effect of high levels of TNF-alpha on various endometrial cell types.

The expression, activity and regulation of granulocyte macrophage-colony stimulating factor in human endometrial epithelial and stromal cells

The expression of granulocyte macrophage-stimulating factor (GM-CSF) and GM-CSF receptors in the human endometrium suggests an autocrine/paracrine role for GM-CSF in this tissue. Using primary cultures of isolated endometrial glandular epithelial and stromal cells, the present study examined: (i) the cell specific expression of GM-CSF and GM-CSF receptor mRNA and protein; (ii) direct action of GM-CSF on the rate of DNA synthesis and cell proliferation; and (iii) regulation of GM-CSF expression through its interaction with transforming growth factor (TGF)-beta1 in these cells. Quantitative reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay and immunocytochemistry indicates that glandular epithelial and stromal cells express GM-CSF, GM-CSF alpha and GM-CSF beta receptor mRNA and protein. The epithelial cells express a significantly higher level of GM-CSF mRNA than stromal cells while both types produce low concentrations of protein. At 0.01-100 ng/ml GM-CSF did not have a significant effect on the rate of [3H]-thymidine incorporation or proliferation of epithelial and stromal cells. However, GM-CSF (1 ng/ ml) up-regulates its own protein expression, but does not effect TGF-beta1 mRNA protein expression in epithelial and stromal cells, and actually inhibits the cell-associated TGF-beta1 protein in stromal cells (P<0.05). At 1 ng/ ml TGF-beta1 up-regulates its own mRNA and protein expression in epithelial and stromal cells (P<0.05), with no significant effect on GM-CSF expression. Co-treatment of the cells with GM-CSF + TGF-beta1 resulted in an increased production of GM-CSF protein as well as TGF-beta1 mRNA and protein expression by epithelial and stromal cells, compared with untreated controls (P<0,001). In conclusion, the results suggest that GM-CSF is not a mitogenic factor for endometrial glandular epithelial and stromal cells, however, in an interactive manner with TGF-beta1 it regulates its own and the expression of TGF-beta1.

Expression of integrin messenger ribonucleic acid in human endometrium: a quantitative reverse transcription polymerase chain reaction study

OBJECTIVE

To assess the expression of selected integrin subunit's messenger RNA (mRNA) in human endometrium during the menstrual cycle.

DESIGN

A prospective comparative study.

SETTING

Academic research environment.

PATIENT(S)

Premenopausal women with histologically normal endometrium who were undergoing hysterectomy.

INTERVENTION(S)

Endometrial tissues were collected.

RESULT(S)

Human endometrium expresses integrins alpha2, alpha3, alpha4, alpha5, alpha6.1, alpha6.2, alpha v, beta1, beta2, beta3, and beta5, as well as fibronectin mRNA. The levels of endometrial integrins mRNA expression varied significantly, with the lowest levels observed for alpha2, beta3, and fibronectin and the highest for alpha5, beta2, and beta5. The levels of integrins alpha2, alpha3, and alpha5 mRNA expression were significantly higher during the proliferative phase, whereas alpha4, alpha6.2, alpha v, beta1, beta2, beta3, beta5, and fibronectin were higher during the secretory phase of the menstrual cycle. The alpha6.1 mRNA was found to be equally expressed in the endometrium during the menstrual cycle, whereas the most dramatic changes occurred in alpha v and beta3 expression, compared with other integrin subunits.

CONCLUSION(S)

Human endometrium expresses mRNA for several integrins and fibronectin, with up-regulation of alpha4, alpha v, beta1, and beta3 during the secretory phase of the menstrual cycle, suggesting that their differential expression may be regulated in part by ovarian steroids.

Differential expression of matrix metalloproteinases and their tissue inhibitors in leiomyomata: a mechanism for gonadotrophin releasing hormone agonist-induced tumour regression

Tissue remodelling involving extracellular matrix (ECM) turnover plays a major role in leiomyoma growth and regression, regulated by the combined action of matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs). We postulated that leiomyomata express MMP and TIMP mRNA and protein, and their expression is inversely regulated during tumour growth and gonadotrophin releasing hormone agonist (GnRHa)-induced regression. We therefore examined the expression of mRNA and protein for MMPs (interstitial collagenase, MMP-1; gelatinases, MMP-2 and MMP-9; and stromelysin, MMP-3) and TIMPs (TIMP-1 and TIMP-2) in leiomyoma and matched unaffected myometrium from GnRHa (lupron)-treated and untreated patients. Reverse transcription-polymerase chain reaction (RT-PCR) and restriction enzyme analysis revealed that leiomyomata and myometrium expressed MMP-1, -2, -3 and -9, as well as TIMP-1 and -2 mRNA. Quantitative RT-PCR indicated that leiomyomata and myometrium during the secretory phase of the menstrual cycle expressed higher levels of MMP and TIMP mRNA compared to the proliferative phase (P < 0.05), with low to undetectable levels of MMP-1, -2 and -3 mRNA in the tumours. GnRHa therapy induced an overall reduction in MMP and TIMP mRNA expression in both leiomyomata and myometrium, but a significant decrease in TIMP-1, and an increase in MMP mRNA expression compared with untreated tumours (P < 0.05). Immunohistochemically, MMP-1, -2, -3 and -9 and TIMP-1 and -2 proteins were localized in leiomyomata and myometrial smooth muscle cells, arteriole wall and connective tissue fibroblasts, with an overall increase in MMP and a decrease in TIMP staining intensity in GnRHa-treated groups. The results suggest that MMP and TIMP expression in leiomyoma and myometrium are hormonally regulated, and that GnRHa-induced tumour regression is accompanied by an increase in MMP expression with a concomitant decrease in TIMP-1 expression, which may potentially provide an environment favouring ECM degradation.

Inhibition of transforming growth factor-beta 1 alters the growth, anchor-dependent cell aggregation and integrin mRNA expression in human promonocytes: implications for endometriosis and peritoneal adhesion formation

Transforming growth factor beta (TGF-beta) is a major secretory product of macrophages which, through autocrine/paracrine pathways, play a central role in normal reproductive tissues as well as in disorders such as endometriosis and intraperitoneal adhesion formation. Using TGF-beta antisense oligonucleotides and U937 cells (a promonocytic human cell line) as an in-vitro model, the present study examined the autocrine mediated action of TGF-beta 1 on proliferation, anchor-dependent and -independent cell aggregation and expression of several mRNAs of cell surface adhesion molecules including integrins and platelet-endothelial cell adhesion molecule (PECAM-1). Northern blot analysis and enzyme-linked inmmunosorbent assay (ELISA) revealed that treatment with TGF-beta 1 antisense, but not sense or nonsense oligomers, in a dose-dependent manner (0.1-10 microM) down-regulated the expression of TGF-beta 1 mRNA and protein to undetectable amounts at the highest antisense concentration. TGF-beta 1 antisense at < 1 mM slightly increased, while at > 3 microM significantly inhibited, the rate of DNA synthesis and proliferation of these cells (P < 0.05). Treatment with TGF-beta 1 antisense promoted cell aggregation under anchor-independent culture conditions (plastic dishes), while it suppressed colony formation under anchor-dependent culture conditions (soft agar assay). U937 cells expressed alpha 2, alpha 3, alpha 4, alpha 5, alpha 6, beta 1 and beta 2 integrin mRNA and PECAM-1 mRNA, while alpha v, beta 3 and beta 5 integrin mRNA was undetectable. The relative amount of alpha 2, alpha 3, alpha 4, alpha 6, beta 1 and beta 2 integrin and PECAM-1 mRNA expression were down-regulated in a dose-dependent manner after TGF-beta 1 antisense treatment, while alpha 5 integrin mRNA expression was up-regulated, although it was undetectable at 10 microM antisense. In contrast, TGF-beta 1 antisense up-regulated beta 3 mRNA expression with maximal effect occurring at 10 microM. These results provide evidence that the autocrine loop of monocyte/macrophage-derived TGF-beta 1 action is essential for regulation of growth, aggregation and the expression of adhesion molecules by these cells. We propose that in disorders such as endometriosis and peritoneal fibrous adhesions, significantly higher numbers of tissue macrophages with the capacity to express excess TGF-beta 1 yield an environment able to promote cell-cell and cell-matrix interactions, and thus lead to further complications from these abnormalities. We are currently investigating whether site-specific inhibition of TGF-beta using antisense strategy is a useful tool for management of these lesions, particularly after their post-surgical removal.

The expression of transforming growth factor-beta s and TGF-beta receptor mRNA and protein and the effect of TGF-beta s on human myometrial smooth muscle cells in vitro

In this study we investigated the expression of transforming growth factor-beta (TGF-beta) isoform and TGF-beta receptor mRNA and protein, and the effect of TGF-beta 1-3 on the rate of DNA synthesis and proliferation of human myometrial smooth muscle cells in vitro. To determine these, we utilized primary cultures of myometrial smooth muscle cells, standard and competitive quantitative reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry, enzyme-linked immunoassay, radioreceptor assay, [3H] thymidine incorporation and cell proliferation assay. Standard RT-PCR and immunocytochemistry revealed that myometrial smooth muscle cells express TGF beta 1-3 and TGF-beta type I-III receptor (TGF-beta R) mRNA and protein. Quantitative RT-PCR, using an external synthetic RNA standard, indicated that the cells express 10 copies/cell of TGF-beta 1 and TGF-beta 2, less than one copy/cell of TGF-beta 3 and TGF-beta type IR, three copies/cell of type IIIR, and > 200 copies/cell, of TGF-beta type IIR mRNA. The cells also synthesized and released TGF-beta 1 at the rate of 7.8 +/- 0.7 ng/10(6) cells, of which 1.4 +/- 0.2 ng/10(6) cells was in an active form. The rate of [3H] thymidine incorporation or proliferation of subconfluent quiescent smooth muscle cells was not altered by TGF-beta s (0.1-10 ng/ml) under serum-free conditions, nor in the presence of 10% fetal bovine serum (FBS). TGF-beta 1-3 at 0.25-0.5 ng/ml in the presence of 2% FBS, which induces half maximal stimulation of these cells, stimulated the rate (P < 0.05), whereas at higher doses it reduced the rate of [3H]-thymidine incorporation compared to the controls. The effect of TGF-beta was partially reversible using neutralizing antibodies specific to TGF-beta 1, TGF-beta 2 (10 micrograms/ml) or TGF-beta 3 (3-6 micrograms/ml). TGF-beta s had no significant effect on cell proliferation determined by cell counting. The data indicate that human myometrial smooth muscle cells express the necessary components of the TGF-beta system, suggesting an autocrine/paracrine role for TGF-beta s in myometrium.