Galectin-1 prolongs survival of mouse liver allografts from Flt3L-pretreated donors

Liver allografts are spontaneously accepted across MHC barriers in mice. The mechanisms underlying this phenomenon remain poorly understood. Galectin-1, an endogenous lectin expressed in lymphoid organs, plays a vital role in maintaining central and peripheral tolerance. This study was to investigate the role of galectin-1 in spontaneous tolerance of liver allografts in mice, and to evaluate the therapeutic effects of galectin-1 on liver allograft rejection induced by donor Flt3L pretreatment. Blockade of the galectin-1 pathway via neutralizing antigalectin-1 mAb did not affect survival of the liver allografts from B6 donors into C3H recipients. Administration of rGal-1 significantly prolonged survival of liver allografts from Flt3L-pretreated donors and ameliorated Flt3L-triggered liver allograft rejection. This effect was associated with increased apoptosis of T cells in both allografts and spleens, decreased frequencies of Th1 and Th17 cells, decreased expression of Th1-associated cytokines (IL-12, IL-2 and IFN-γ), Th17-associated cytokines (IL-23 and IL-17) and granzyme B, in parallel with selectively increased IL-10 expression in liver allografts. In vitro, galectin-1 inhibited Flt3L-differentiated DC-mediated proliferation of allo-CD4(+) T cells and production of IFN-γ and IL-17. These data provide new evidence of the potential regulatory effects of galectin-1 in alloimmune responses in a murine model of liver transplantation.

Effect of erythropoietin on mesenchymal stem cell differentiation and secretion in vitro in an acute kidney injury microenvironment

We investigated the effect of erythropoietin (EPO) on differentiation and secretion of bone marrow-derived mesenchymal stem cells in an acute kidney injury microenvironment. Acute kidney injury mouse models were prepared. Both renal cortices were then immediately collected to produce the ischemia/reperfusion kidney homogenate supernatant. The morphological and ultrastructural changes in the cells were observed using an inverted microscope and a transmission electron microscope. Cytokeratin-18 was detected using flow cytometry. Bone morphogenetic protein-7 levels, hepatocyte growth factor, and vascular endothelial growth factor in the culture medium were detected using an enzyme-linked immunosorbent assay. The cells had high CD29 and CD44 expression, as well as low CD34 and CD45 expression. More round and oval cells with cobble-like appearances were observed after EPO treatment. In addition, an increase in the number of rough endoplasmic reticula, lysosomes, and mitochondria was observed in the cytoplasm; the intercellular junction peculiar to epithelial cells was also seen on the cell surface. After treatment with ischemia/reperfusion kidney homogenate supernatant, cytokeratin-18 expression increased significantly and EPO could magnify its expression. Bone morphogenetic protein-7 levels, hepatocyte growth factor, and vascular endothelial growth factor levels after treatment with ischemia/reperfusion kidney homogenate supernatant significantly decreased, whereas EPO increased the cytokine secretion. The acute kidney injury microenvironment can induce the bone marrow-derived mesenchymal stem cells to partially differentiate into renal tubular epithelium-shaped cells, but weaken their secretion function. EPO intervention can boost up their differentiation function and reverse their low secretion effect.

T cell-derived leptin contributes to increased frequency of T helper type 17 cells in female patients with Hashimoto's thyroiditis

Leptin modulates T cell function and plays an important role in autoimmune diseases. Our study aimed to explore the role of leptin and T helper type 17 (Th17) cells in Hashimoto's thyroiditis patients. Twenty-seven patients with Hashimoto's thyroiditis (HT) and 20 healthy controls were enrolled into the current study. A modest increase of plasma leptin in HT patients and the CD4(+) T cell-derived leptin from HT patients was stronger than that from healthy controls. In HT patients, there are no statistically significant correlations between plasma leptin concentrations and the percentage of Th17 cells or the level of retinoic acid-related orphan receptor γt (RORγt), but strong positive correlations were observed between CD4(+) T cell-derived leptin and the percentage of Th17 cells or the level of RORγt mRNA, and additionally significantly up-regulated leptin, interleukin (IL)17 and RORγt mRNA levels in the thyroid tissue. Furthermore, neutralization of leptin decreases the frequency of Th17 cells in vitro. Current study has revealed an increased leptin involvment in Hashimoto's thyroiditis associated with an increased number of Th17 cells.

Usefulness of specific OA biomarkers, thrombin-cleaved osteopontin, in the posterior cruciate ligament OA rabbit model

OBJECTIVE

We undertook this study to determine whether thrombin-cleaved osteopontin (OPN) in synovial fluid (SF) represents a useful marker of osteoarthritis (OA) progression in the posterior cruciate ligament transection (PCLT) OA rabbit model.

METHOD

PCLT was performed on the right knee joints of 48 rabbits. The rabbits were then sacrificed separately at 4, 8, 16, and 24 weeks post-surgery, when the joint was harvested and macroscopic and histological assessments of articular cartilage were performed. Thrombin-cleaved OPN product in SF was determined using Western blotting and the levels were measured using an enzyme-linked immunoassay.

RESULTS

The macroscopic and histological scores for PCLT knees were already elevated 4 weeks after surgery and increased with time. Western blotting showed the presence of thrombin-cleaved OPN in SF from PCLT knees. Thrombin-cleaved OPN levels in SF were elevated at 4 weeks (P < 0.001) and were elevated peaking at 24 weeks (P < 0.00001) after PCLT compared to baseline. A positive significant correlation was found between thrombin-cleaved OPN levels and the macroscopic scores (8 weeks: ρ = 0.695, P = 0.012; 16 weeks: ρ = 0.751, P = 0.005; 24 weeks: ρ = 0.660, P = 0.020). Furthermore, the same correlation was noted between thrombin-cleaved OPN levels and the histological scores (4 weeks: ρ = 0.609, P = 0.036; 8 weeks: ρ = 0.662, P = 0.019; 16 weeks: ρ = 0.827, P = 0.001; 24 weeks: ρ = 0.813, P = 0.001).

CONCLUSION

In this rabbit model of PCLT, thrombin-cleaved OPN levels in SF appear to provide a useful marker of OA disease severity and progression.

A simple novel technique for heterotopic intestinal transplantation in mice

The murine heterotopic intestinal transplant model is of particular value for addressing the unique immune response in the gut and addressing the underlying immune mechanism during transplantation. Anastomotic stenosis, anastomotic bleeding, and septic shock continue to hamper procedures and plague the success. In this study, we assessed a refined technique designed to improve the success of heterotopic intestinal transplant in mice. Important factors in our refined technique included (1) a refined procedure for graft portal vein preparation, (2) a novel procedure for graft exteriorization, and most importantly (3) a knotless suturing technique designed to allow the surgeon to alter the size of the anastomosis, thus reducing anastomotic bleeding and stenosis rate. Our refined knotless method improved recipient survival to 67.5% when compared to the standard technique (53.8%). In comparison to standard knot suturing technique, which had an anastomotic stenosis rate of 8.3%, the knotless suturing technique significantly reduced the rate of anastomotic stenosis to only 2.4%. Anastomotic bleeding presented in the knotless technique in only 1.2%, whereas it presented in 6.2%, of mice in the standard technique (P < .05). This refined knotless technique offers an easy and effective method for murine heterotopic intestinal transplantation.

IL-17 and IFN-γ production in peripheral blood following BCG vaccination and Mycobacterium tuberculosis infection in human

BACKGROUND

During Mycobacterium tuberculosis (Mtb) infection, cells of the immune system rely on cytokines to regulate the activity of other immune and structural cells such as IFN-gamma and IL-4. Recent studies suggest that Th17 cells secreting IL-17 may play a potential role in tuberculosis (TB) development.

AIM

To assess the effect of IL-17 on TB development, we provide a systematic review on the production of IL-17, IFN-gamma and IL-4 in infants or children vaccinated with BCG and in TB patients.

MATERIALS AND METHODS

The literature relevant with IL-17 and IFN-gamma production with or without IL-4 on human TB was retrieved from PubMed, EMBASE, Cochrane Library, BIOSIS Previews and the China Biomedicine Literature Databases (CBM) using the search terms "Interleukin-17 or Th17 cells" and "Tuberculosis". The information of included studies, the production of IL-17 and IFN-gamma responding to antigens in the peripheral blood in vitro, was independently extracted by the first two researchers and subsequently qualitatively analyzed.

RESULTS

Nine studies from a total of 226 retrieved publications met the criteria. These included studies showed that BCG vaccination induced dramatically high level of IL-17 similar to IFN-gamma; The level of IL-17 and IFN-gamma were low while IL-4 was high in patients with active TB; IL-17 and IFN-gamma had a similar trend of increase during the conversion from active to latent TB while IL-4 inclined to decrease in this process.

CONCLUSIONS

IL-17 acts as an effector molecule similar to IFN-gamma after BCG vaccination and Mtb infection to protect human against TB. The current findings do not support IL-17 as an inducer of tissue damage in TB.

A novel lentivirus for quantitative assessment of gene knockdown in stem cell differentiation

Loss of gene function is a valuable tool for screening genes in cellular processes including stem cell differentiation differentiation. However, the criteria for evaluating gene knockdown are usually based on end-point analysis and real-time, dynamic information is lacking. To overcome these limitations, we engineered a shRNA encoding LentiViral Dual Promoter vector (shLVDP) that enabled real-time monitoring of mesenchymal stem (MSC) differentiation and simultaneous gene knockdown. In this vector, the activity of the alpha-smooth muscle actin (αSMA) promoter was measured by the expression of a destabilized green fluorescent protein, and was used as an indicator of myogenic differentiation; constitutive expression of discosoma red fluorescent protein was used to measure transduction efficiency and to normalize αSMA promoter activity; and shRNA was encoded by a doxycycline (Dox)-regulatable H1 promoter. Importantly, the normalized promoter activity was independent of lentivirus titer allowing quantitative assessment of gene knockdown. Using this vector, we evaluated 11 genes in the TGF-β1 or Rho signaling pathway on SMC maturation and on MSC differentiation along the myogenic lineage. As expected, knockdown of genes such as Smad2/3 or RhoA inhibited myogenic differentiation, while knocking down the myogenic differentiation inhibitor, Klf4, increased αSMA promoter activity significantly. Notably, some genes for example, Smad7 or KLF4 showed differential regulation of myogenic differentiation in MSC from different anatomic locations such as bone marrow and hair follicles. Finally, Dox-regulatable shRNA expression enabled temporal control of gene knockdown and provided dynamic information on the effect of different genes on myogenic phenotype. Our data suggests that shLVDP may be ideal for development of lentiviral microarrays to decipher gene regulatory networks of complex biological processes such as stem cell differentiation or reprogramming.

Induction of microRNA-24 by HIF-1 protects against ischemic injury in rat cardiomyocytes

MicroRNAs are emerging as important regulators of cardiac function. This study investigated the role of microRNA-24 (miR-24) in ischemic cardiomyocytes, based on the observation that miR-24 expression was significantly enhanced in the ischemic myocardium of rats. Using primary cultured rat cardiomyocytes, cell injury was induced by ischemic conditions, and the cells were evaluated for changes in lactate dehydrogenase (LDH) release, cell viability, apoptosis and necrosis. The results showed that miR-24 was increased in myocytes exposed to ischemia. When miR-24 was further overexpressed in ischemic myocytes using the mimic RNA sequence, LDH release was reduced, cell viability was enhanced, and apoptosis and necrosis rates were both decreased. By contrast, a deficiency in miR-24 resulted in the largest LDH release, lowest cell viability and highest apoptosis and necrosis rates in normal and ischemic myocytes, with significant changes compared to that of non-transfected myocytes. Additionally, the mRNA and protein levels of the pro-apoptotic gene, BCL2L11, were down-regulated by miR-24 overexpression and up-regulated by miR-24 deficiency. The luciferase reporter assay confirmed BCL2L11 to be a target of miR-24. Overall, this study showed a protective role for miR-24 against myocardial ischemia by inhibiting BCL2L11, and may represent a potential novel treatment for ischemic heart disease.

Combination therapy an ACE inhibitor and an angiotensin receptor blocker for IgA nephropathy: a meta-analysis

OBJECTIVE

The pathogenesis of IgA nephropathy (IgAN) is still unknown. Combination therapy with angiotensin-converting enzyme inhibitors (ACEIs) plus angiotensin receptor blockers (ARBs) might provide more benefits to IgAN patients. We conducted a systematic review to assess the efficacy of combination therapy for IgAN.

METHODS

The MEDLINE, EMBASE, the Cochrane Library and article reference lists were searched for randomised clinical trials (RCTs) which involved combination therapy ACEI plus ARB in only one arm. A meta-analysis was performed on the outcomes of proteinuria and renal function in IgAN patients.

RESULTS

Six RCTs involving 109 patients were included in the review. Combined treatment with ACEI plus ARB was more effective than with ACEI/ARB alone for reducing daily proteinuria. This did not translate into an improvement in GFR. Patients receiving ACEI plus ARB therapy did not have an increased risk of hyperkalemia.

CONCLUSIONS

The current cumulative evidence suggests that combination therapy ACEI plus ARB may provide more benefits to IgAN patients for reducing daily proteinuria. Long-term effects of these agents on renal outcomes, and safety need to be established.

Simultaneous bilateral hip joint imaging at 7 Tesla using fast transmit B₁ shimming methods and multichannel transmission - a feasibility study

The objective of this study was to demonstrate the feasibility of simultaneous bilateral hip imaging at 7 Tesla. Hip joint MRI becomes clinically critical since recent advances have made hip arthroscopy an efficacious approach to treat a variety of early hip diseases. The success of these treatments requires a reliable and accurate diagnosis of intraarticular abnormalities at an early stage. Articular cartilage assessment is especially important to guide surgical decisions but is difficult to achieve with current MR methods. Because of gains in tissue contrast and spatial resolution reported at ultra high magnetic fields, there are strong expectations that imaging the hip joint at 7 Tesla will improve diagnostic accuracy. Furthermore, there is growing evidence that the majority of these hip abnormalities occur bilaterally, emphasizing the need for bilateral imaging. However, obtaining high quality images in the human torso, in particular of both hips simultaneously, must overcome a major challenge arising from the damped traveling wave behaviour of RF waves at 7 Tesla that leads to severe inhomogeneities in transmit B1 (B(1) (+) ) phase and magnitude, typically resulting in areas of low signal and contrast, and consequently impairing use for clinical applications. To overcome this problem, a 16-channel stripline transceiver RF coil was used, together with a B1 shimming algorithm aiming at maximizing B(1) (+) in six regions of interest over the hips that were identified on axial scout images. Our successful results demonstrate that this approach effectively reduces inhomogeneities observed before B1 shimming and provides high joint tissue contrast in both hips while reducing the required RF power. Critical to this success was a fast small flip angle B(1) (+) calibration scan that permitted the computation of subject-specific B1 shimming solutions, a necessary step to account for large spatial variations in B(1) (+) phase observed in different subjects.

MicroRNA-337 is associated with chondrogenesis through regulating TGFBR2 expression

OBJECTIVE

MicroRNAs (miRNAs) have been implicated in regulating diverse cellular pathways and involved in development and inflammation. This study aimed to examine six miRNAs expression during the cartilage development and identify the key miRNA which is associated with chondrogenesis.

METHODS

The expression of six miRNAs in cartilage tissue during development was screened by real-time quantitative polymerase chain reaction (RT-qPCR). Rat models of bone matrix gelatin induced endochondral ossification, collagen-induced arthritis and pristane-induced arthritis were established to examine whether miR-337 is involved in chondrogenesis. Furthermore, the regulation of transforming growth factor-b type II receptor (TGFBR2) expression by miR-337 was determined with the luciferase reporter gene assay and Western blot. The expression of some specific genes relevant to cartilage tissue was tested by RT-qPCR after miR-337 mimic or inhibitor transfection.

RESULTS

MiR-337 expression was significantly down-regulated and almost disappeared in the maturation phases of endochondral ossification. The results of histology and RT-qPCR from three rat models showed that miR-337 is directly bound up with chondrogenesis. Furthermore, the results from the luciferase reporter gene assay and Western blot indicated that miR-337 regulated TGFBR2 expression. Our study also found that the enhancement of miR-337 may modulate the expression of cartilage-specific genes such as AGC1 in C-28/I2 chondrocytes.

CONCLUSION

We proved that miRNA-337 is associated with chondrogenesis through regulating TGFBR2 expression, and miRNA-337 can also influence cartilage-specific gene expression in chondrocytes. These findings may provide an important clue for further research in the arthritis pathogenesis and suggest a new remedy for arthritis treatment.

Directed flow of identified particles in Au+Au collisions at √[SNN]=200 GeV at RHIC

STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

Peak expiratory flow as a screening tool to detect airflow obstruction in a primary health care setting

BACKGROUND

Peak expiratory flow (PEF) measurement is less expensive and requires fewer skills than spirometry testing. It is thus expected to be a reasonable substitute for spirometry in airflow obstruction screening when spirometry is unavailable.

OBJECTIVES

To evaluate the validation of PEF measurement in the detection of airflow obstruction using newly established regression equations.

METHODS

The PEFs of 553 'normal' participants aged 40-85 years were measured using mechanical devices. Based on these data, regression equations were generated to predict normal PEF values. Data were then collected from 3379 subjects. The specificity and sensitivity of the different predicted PEF cut-off points for detecting airflow obstruction were evaluated by spirometry, based on previously generated regression equations.

RESULTS

Using newly established reference values for PEF, PEF had higher sensitivity and specificity than the questionnaire in detection of airflow obstruction. That PEF < 80% of predicted was more effective in the detection of airflow obstruction was confirmed by the lower limit of normal of forced expiratory volume in 1 second/forced vital capacity, Global Initiative for Chronic Obstructive Lung Disease (GOLD), and GOLD plus symptom, with a sensitivity of 78.7%, 76.8%, 85.3% and a specificity of 81.9%, 83.8%, 81.4%, respectively.

CONCLUSIONS

Mechanical PEF may be a reasonable method of screening for airflow obstruction in settings where spirometry is unavailable.

Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at √S(NN)=200 GeV

We report transverse momentum (p(T)≤15  GeV/c) spectra of π(±), K(±), p, p[over ¯], K(S)(0), and ρ(0) at midrapidity in p+p and Au+Au collisions at √S(NN)=200  GeV. Perturbative QCD calculations are consistent with π(±) spectra in p+p collisions but do not reproduce K and p(p[over ¯]) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au+Au at p(T)≳8  GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.

Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV

We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200  GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200  GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.