Human lactoferrin stimulates skin keratinocyte function and wound re-epithelialization

BACKGROUND

Human lactoferrin (hLF), a member of the transferrin family, is known for its antimicrobial and anti-inflammatory effects. Recent studies on various nonskin cell lines indicate that hLF may have a stimulatory effect on cell proliferation.

OBJECTIVES

To study the potential role of hLF in wound re-epithelialization.

MATERIALS AND METHODS

The effects of hLF on cell growth, migration, attachment and survival were assessed, with a rice-derived recombinant hLF (holo-rhLF), using proliferation analysis, scratch migration assay, calcein-AM/propidium iodide staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) method, respectively. The mechanisms of hLF on cell proliferation and migration were explored using specific pathway inhibitors. The involvement of lactoferrin receptor low-density lipoprotein receptor-related protein 1 (LRP1) was examined with RNA interference technique. An in vivo swine second-degree burn wound model was also used to assess wound re-epithelialization.

RESULTS

Studies revealed that holo-rhLF significantly stimulated keratinocyte proliferation which could be blocked by mitogen-activated protein kinase (MAPK) kinase 1 inhibitor. Holo-rhLF also showed strong promoting effects on keratinocyte migration, which could be blocked by either inhibition of the MAPK, Src and Rho/ROCK pathways, or downregulation of the LRP1 receptor. With cells under starving or 12-O-tetradecanoylphorbol-13-acetate exposure, the addition of holo-rhLF was found greatly to increase cell viability and inhibit cell apoptosis. Additionally, holo-rhLF significantly increased the rate of wound re-epithelialization in swine second-degree burn wounds.

CONCLUSIONS

Our studies demonstrate the direct effects of holo-rhLF on wound re-epithelialization including the enhancement of keratinocyte proliferation and migration as well as the protection of cells from apoptosis. The data strongly indicate its potential therapeutic applications in wound healing.

c-Abl and Arg tyrosine kinases regulate lysosomal degradation of the oncoprotein Galectin-3

Galectin-3 (Gal3) has important roles in tumor transformation and metastasis. This study shows that c-Abl and Abl-related gene (Arg) associate with and phosphorylate Gal3. The SH (Src homology)3 domains of c-Abl/Arg bind to a P(80)GPPSGP motif of Gal3, and Tyr79 and Tyr118 are the major tyrosine phosphorylation sites. A consequence of this interaction and phosphorylation is the significant impairment of chaperone-mediated autophagy of Gal3. Cells expressing Gal3 and treated with the c-Abl/Arg inhibitor STI571, Gal3-depleted cells, and Gal3-depleted cells expressing Gal3 phosphorylation mutants all display an increased sensitivity to apoptosis-inducing agents. In addition, tumor cells expressing the phosphorylation mutants show impaired tumorigenicity. These results partially explain the antiapoptotic effect of Abl and Arg. As tumors frequently overexpress Gal3, a c-Abl/Arg-specific inhibitor may potentially be applied along with other antitumor drugs to target the lysosomal degradation of Gal3 in tumor therapy.

Efficacy and safety of pegylated interferon alpha-2a therapy for chronic hepatitis C in HIV-infected patients with haemophilia

The objective of this study was to evaluate the efficacy and safety of pegylated interferon (PEG-IFN) alpha-2a monotherapy in a cohort of Chinese haemophilic patients co-infected with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) and undergoing highly active antiretroviral drugs therapy. Twenty-two (n = 22) patients with CD4 lymphocyte counts over 200 cells microL(-1) were treated with 180 microg of PEG-IFN alpha-2a subcutaneously once in a week for 48 weeks. HCV load (HCV RNA), HIV load (HIV RNA) and CD4 lymphocyte counts were measured at baseline and 4, 12, 24, 48 and 72 weeks after initiation of anti-HCV therapy. Efficacy and safety were analysed according to baseline CD4 status (> or =350 cells microL(-1)). Significant HCV-RNA decreases (>1 log(10) copies mL(-1)) were observed through week 72 after PEG-INF alpha-2a monotherapy across both CD4 strata. CD4 status was not associated with treatment outcomes as evaluated using rapid viral response rate (P = 0.655), early viral response rate (P = 0.387), end-of-treatment viral response rate (P = 1.000) or sustained viral response rate (SVR, P = 0.674). A sustained virological response was achieved in nine patients (41%), five with genotype 2a (83%) and four with genotype 1b (25%, P = 0.023). SVR was HCV genotype dependent. Eleven patients required a dose reduction in PEG-IFN alpha-2a. PEG-IFN alpha-2a monotherapy could be considered as a safe and effective option for the treatment of HCV infection in HIV patients with haemophilia, particularly in resource-limited settings. While higher CD4 lymphocyte counts resulted in greater HCV-RNA reduction, HCV genotype was a predictor for sustained virological response.

Phase I trial of advanced generation anti-CEA designer T cells in gastrointestinal and breast cancers

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Background: We created “designer T cells” by retroviral gene therapy to express chimeric immunoglobulin-T cell receptors (IgTCR) with specificity for carcinoembryonic antigen (CEA). Our previous Phase I trial with 1st generation (1st gen) designer T cells was well tolerated with proof-of-principle “biologic responses”, but of limited duration. Lab correlates showed modified T cells repeatedly kill tumor targets over 4–7 days but then undergo activation-induced cell death (AICD). We created 2nd gen designer T cells that incorporate CD28 co-stimulation into the IgTCR (IgCD28TCR), suppressing AICD and promoting T cell proliferation on tumor contact with superior tumor responses in vivo (Emtage et al. Clin Cancer Res 2008;14:8112). A Phase I clinical trial was approved under FDA BB-IND 10791. Methods: Patient T cells are modified ex vivo, expanded and then administered in a Phase Ia dose escalation, spanning doses of 10^9 to 10^11 cells. Patients are monitored for safety, pharmacokinetics and response. Results: To date, three subjects enrolled with doses prepared and two were treated. T cells were transduced with equal modification of CD4 helper and CD8 cytotoxic T cells and good ex vivo expansions of 30-fold or more. Cells were infused over 15–30 minutes. Blood clearance was rapid. Dosing was without toxicity but also without responses at this lowest T cell dose level. Results will be updated to include new patients at conference time. Conclusions: The safety of 2nd generation designer T cells is supported in two patients at the lowest T cell dose level. Higher planned doses are 10- to 100-fold more T cells, to be observed for toxicity and where responses may begin to be observed. Funding is from the Office of Orphan Products Development of the FDA.

No significant financial relationships to disclose.

Phase I trial of anti-PSMA designer T-cell autografting in prostate cancer

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Background: We created chimeric immunoglobulin-T cell receptors (IgTCR) specific for prostate specific membrane antigen (PSMA). When expressed in patient T cells, these “designer T cells” specifically kill prostate cancer cells in vitro and in vivo in animal models, with 5/9 (55%) of xenografted mice experiencing complete remissions (Ma et al. Prostate 2004:61:12–25). A Phase I clinical trial was approved by the FDA in metastatic prostate cancers. Methods: Patient T cells are retrovirally transduced and expanded ex vivo to span dose levels of 10^9 to 10^11 T cells. Adapting methods of Dudley, Rosenberg and colleagues, patients undergo prior non-myeloablative (NMA) conditioning to create a “hematologic space” into which the infused designer T cells will stably engraft for prolonged in vivo efficacy. Patients are co-administered continuous infusion IL2. Outcomes will include Phase Ia goals of safety and toxicity and Phase Ib goals of establishing an optimal biologic dose in terms of designer T cell engraftment and tumor response. Results: For the first two patients, excellent T cell modifications of 50–60% were obtained. After NMA conditioning, T cells were infused and stable engraftments of 1–5% were observed post recovery, even at this lowest 10^9 T cell dose level, thus affirming one of the study end-points. The patients had PSA reductions of 50 and 70% in the two months following treatment. Patients experienced neutropenia and lymphopenia after conditioning, but no designer T cell-related toxicities. Results with additional patients will be described in terms of safety, engraftment efficiency and tumor responses. Conclusions: A new approach to adoptive immune therapy in metastatic prostate cancer has been devised. This clinical trial is funded by the US Army/DOD.

No significant financial relationships to disclose.

Blockade of SDF-1/CXCR4 signalling inhibits pancreatic cancer progression in vitro via inactivation of canonical Wnt pathway

Extra-pancreatic metastasis is a difficult problem for surgical intervention in pancreatic cancer. CXC chemokine receptor 4 (CXCR4) was considered to have an important role in this process. We hypothesized it may contribute to the pancreatic cancer progression through influencing canonical Wnt pathway. The purpose of this study was to examine the functional role of CXCR4 in the progression of pancreatic cancers and explore the possible mechanism. To this end, the relation between CXCR4 and clinical characteristics was analysed. shRNA against CXCR4 was applied to disrupt the SDF-1/CXCR4 signal transduction pathways in pancreatic cancer cell lines. Our results showed that overall survival in the case of patients positive for CXCR4 expression was significantly lower than that in the case of patients negative for CXCR4 expression. Notably, in vitro studies we observed that the abrogation of CXCR4 could obviously influence the pancreatic cancer cell phenotype including cell proliferation, colony formation, cell invasion and also inhibit the TOPflash activity. In addition, Wnt target genes and mesenchymal markers such as Vimentin and Slug were also inhibited in CXCR4 knockdown cells. Collectively, these data reported here demonstrate CXCR4 could modulate the canonical Wnt pathway and perhaps be a promising therapeutic target for pancreatic cancer progression.

Temperature dependences of mechanisms responsible for the water-vapor continuum absorption. I. Far wings of allowed lines

It is well known that the water-vapor continuum plays an important role in the radiative balance in the Earth's atmosphere. This was first discovered by Elsasser almost 70 years ago, and since that time there has been a large body of work, both experimental and theoretical, on this topic. It has been experimentally shown that for ambient atmospheric conditions, the continuum absorption scales quadratically with the H(2)O number density and has a strong, negative temperature dependence (T dependence). Over the years, there have been three different theoretical mechanisms postulated: Far wings of allowed transitions, water dimers, and collision-induced absorption. Despite the improvements in experimental data, at present there is no consensus on which mechanism is primarily responsible for the absorption. The first mechanism proposed was the accumulation of the far-wing absorption of the strong allowed transitions. Later, absorption by water dimers was proposed and this mechanism provides a qualitative explanation for the strong, negative T dependence. Recently, some atmospheric modelers have proposed that collision-induced absorption is one of the major contributors. However, based on improvements in the theoretical calculation of accurate far-wing line shapes, ab initio dimer calculations, and theoretical collision-induced absorptions, it is now generally accepted that the dominant mechanism for the absorption in the infrared (IR) windows is that due to the far wings. Whether this is true for other spectral regions is not presently established. Although all these three mechanisms have a negative T dependence, their T dependences will be characterized by individual features. To analyze the characteristics of the latter will enable one to assess their roles with more certainty. In this paper, we present a detailed study of the T dependence of the far-wing absorption mechanism. We will then compare our theoretical calculations with the most recent and accurate experimental data in the IR windows. The results of our calculations are found to agree very well with measurements in the 800-1200 cm(-1) region. We conclude from this work that the T dependence in the IR window region predicted by the far-wing theory is negative and moderately strong. Its pattern is not simple and it could vary significantly as the frequency of interest varies.

Pharmacological targeting of C5a receptors during organ preservation improves kidney graft survival

Cadaveric renal transplants suffer frequently from delayed graft function, which is associated with increased risk for long-term graft survival loss. One-third of kidney grafts that are stored in current organ preservation solutions experience delayed graft function, demonstrating the urgent need for improvement. Although ischaemic graft injury is complex in nature, complement activation is considered important to the process. Here we show that pharmacological targeting of the complement 5a receptor (C5aR) during cold ischaemia has a protective effect on early kidney graft survival, inflammation and apoptosis in a mouse model of syngeneic kidney transplantation. Graft survival of kidneys that were stored in University of Wisconsin solution in the presence of a C5aR antagonist increased from 29% to 57%. Increased graft survival was associated with less tubular damage and apoptosis, protection from sustained C5aR expression and decreased production of tumour necrosis factor-alpha and macrophage inflammatory protein-2. In a translational approach, we determined C5aR expression in paediatric living-related and cadaveric allografts. C5aR expression was significantly higher in all compartments of kidneys from cadaveric compared with kidneys from living-related donors. C5aR expression in cadaveric kidneys correlated positively with cold ischaemia time, renal dysfunction and the frequency of apoptotic tubular cells, suggesting a novel role for C5a in delayed graft function pathogenesis. Supplementing organ preservation solutions with C5aR inhibitors may improve early graft function following cadaveric kidney transplantation.

Hydraulic lift by canola plants aids P and K uptake from dry topsoil

The role of hydraulic lift in nutrient uptake from dry topsoil is unclear. Vertically-split root systems were used to measure hydraulic lift and phosphorus (P) and potassium (K) uptake at the rosette and flowering stages of two canola (Brassica napus L.) cultivars (Trigold and Boomer with small and large root systems, respectively) grown in soil low in P and K. Rubidium (Rb) was used as a tracer to examine K uptake from K fertiliser banded in dry topsoil. During vegetative growth, statistically significant hydraulic lift was measured, irrespective of cultivar root size or a specific nutrient (P or K) placed in the topsoil. The Rb tracer revealed significant amounts of K were absorbed from the dry soil, but at rates five-fold lower than from the moist soil. The water lifted could not prevent cessation of P uptake by Boomer and a reduction in P uptake by Trigold. During mid to late flowering, ion uptake from the dry topsoil was impeded despite the continuation of hydraulic lift up to 28 days after the topsoil was dried. Minimal fine root growth following topsoil drying (and reduction in fine root biomass in some treatments) appeared to be the primary cause of impeded nutrient uptake.

Bifurcation diagram and pattern formation of phase slip centers in superconducting wires driven with electric currents

We provide here new insights into the classical problem of a one-dimensional superconducting wire exposed to an applied electric current using the time-dependent Ginzburg-Landau model. The most striking feature of this system is the well-known appearance of oscillatory solutions exhibiting phase slip centers (PSC's) where the order parameter vanishes. Retaining temperature and applied current as parameters, we present a simple yet definitive explanation of the mechanism within this nonlinear model that leads to the PSC phenomenon and we establish where in parameter space these oscillatory solutions can be found. One of the most interesting features of the analysis is the evident collision of real eigenvalues of the associated PT-symmetric linearization, leading as it does to the emergence of complex elements of the spectrum.

Beta-globin gene cluster polymorphisms are strongly associated with severity of HbE/beta(0)-thalassemia

We evaluated the contribution of 67 single nucleotide polymorphisms (SNPs) within the beta-globin gene cluster to disease severity in groups of 207 mild- and 305 severe unrelated patients from Thailand with Hemoglobin E (HbE)/beta(0)-thalassemia and normal alpha-globin genes. Our analysis showed that these SNPs comprise two distinct linkage disequilibrium blocks, one containing the beta-globin gene and the other extending from the locus control region (LCR) to the delta gene, which are separated by a recombination hotspot in the narrow region of the beta-globin gene promoter. Forty-five SNPs within the interval including the LCR region and the delta gene showed strong association with disease severity. The strongest association was observed with the XmnI polymorphism located 158-bp upstream to the G gamma gene (p = 4.6E-12). Carriers of the T allele of XmnI were more likely to have a milder disease course and higher level of fetal hemoglobin (HbF) in both the mild (p = 0.005) and severe (p = 8.7E-06) patient groups. Haplotype analysis revealed that the T allele of XmnI was nearly always in cis with the HbE allele. The high frequency of this haplotype may be favored by positive selection against malarial infection. Further studies are needed to validate this hypothesis and determine whether XmnI or another closely linked variant modulates severity and HbF levels in patients with beta(0)-thalassemia/HbE disease.

Fetal hemoglobin in sickle cell anemia: genetic determinants of response to hydroxyurea

The increase in fetal hemoglobin (HbF) in response to hydroxyurea (HU) varies among patients with sickle cell anemia. Twenty-nine candidate genes within loci previously reported to be linked to HbF level (6q22.3-q23.2, 8q11-q12 and Xp22.2-p22.3), involved in metabolism of HU and related to erythroid progenitor proliferation were studied in 137 sickle cell anemia patients treated with HU. Three-hundred and twenty tagging single nucleotide polymorphisms (SNPs) for genotyping were selected based on HapMap data. Multiple linear regression and the nonlinear regression Random Forest method were used to investigate the association between SNPs and the change in HbF level after 2 years of treatment with HU. Both methods revealed that SNPs in genes within the 6q22.3-23.2 and 8q11-q12 linkage peaks, and also the ARG2, FLT1, HAO2 and NOS1 genes were associated with the HbF response to HU. Polymorphisms in genes regulating HbF expression, HU metabolism and erythroid progenitor proliferation might modulate the patient response to HU.

The enhancement of cellular cAMP with olprinone protects autotransplanted rat kidney against cold ischemia-reperfusion injury

The administration of a cyclic nucleotide analog improves cold ischemia/reperfusion injury in several organs. The type 3 phosphodiesterase inhibitor olprinone is a potent stimulus that enhances cellular cAMP levels. The present study was performed to investigate the protective effects of enhanced intracellular cAMP levels by olprinone in rat orthotopic kidney transplantation. Autotransplantation and immediate contralateral nephrectomy were performed in Lewis rats after 18 hours of graft storage at 4 degrees C in University of Wisconsin (UW) solution with or without 25 microg/mL olprinone hydrochloride. At 2 hours after reperfusion, serum and urinary biochemical indicators of renal dysfunction and injury were measured: serum creatinine, fractional excretion of Na+ and urinary N-acetyl-D-glucosaminidase. Additionally, intracellular cAMP in kidney tissues was measured by a radioimmunology method. Compared to the only UW solution group, olprinone hydrochloride significantly reduced the increased in serum creatinine, FENa and NAG caused by renal ischemia/reperfusion injury, after 2 hours of reperfusion. The content of cAMP at the endpoint of 18 hours cold preservation was significantly greater in the UW plus olprinone hydrochloride group than that in the UW group. Two hours after reperfusion, the content of cAMP in the UW plus olprinone hydrochloride group was still significantly higher than that in the UW group without containing olprinone hydrochloride. These results support a beneficial effect of olprinone against cold ischemia and reperfusion injury via an increased intracellular cAMP levels.

HIV-1 coreceptors CCR5 and CXCR4 both mediate neuronal cell death but CCR5 paradoxically can also contribute to protection

The chemokine receptors CCR5 and CXCR4 serve, in addition to CD4, as coreceptors for human immunodeficiency virus-1 (HIV-1), and infection with HIV-1 can cause dementia. In brain-derived cells, HIV-1 envelope glycoprotein gp120 initiates a signaling cascade that involves p38 mitogen-activated protein kinase and leads to neuronal cell death. Using mixed neuronal/glial cultures from rats and mice genetically deficient in one or both HIV coreceptors, we show here that CCR5, CXCR4 or both can mediate HIV/gp120 neurotoxicity depending on the viral strain. Paradoxically, we also found evidence for a CCR5-mediated neuroprotective pathway. We identify protein kinase Akt/PKB as an essential component of this pathway, which can be triggered by the CCR5 agonists macrophage inflammatory protein-1beta and regulated-and-normal-T-cell-expressed-and-secreted. Moreover, these CCR5 ligands prevent neuronal cell death induced by stromal cell-derived factor-1, a CXCR4 agonist. Both neurons and glia coexpress CXCR4 and CCR5. Ca2+ imaging experiments demonstrate that engagement of CCR5 prevents CXCR4-triggered increases in intracellular free Ca2+. This finding suggests that CCR5 ligands can protect neurons at least, in part, by modulating CXCR4-mediated toxicity through heterologous desensitization.

Urine NGAL and IL-18 are predictive biomarkers for delayed graft function following kidney transplantation

Delayed graft function (DGF) due to tubule cell injury frequently complicates deceased donor kidney transplants. We tested whether urinary neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) represent early biomarkers for DGF (defined as dialysis requirement within the first week after transplantation). Urine samples collected on day 0 from recipients of living donor kidneys (n = 23), deceased donor kidneys with prompt graft function (n = 20) and deceased donor kidneys with DGF (n = 10) were analyzed in a double blind fashion by ELISA for NGAL and IL-18. In patients with DGF, peak postoperative serum creatinine requiring dialysis typically occurred 2-4 days after transplant. Urine NGAL and IL-18 values were significantly different in the three groups on day 0, with maximally elevated levels noted in the DGF group (p < 0.0001). The receiver-operating characteristic curve for prediction of DGF based on urine NGAL or IL-18 at day 0 showed an area under the curve of 0.9 for both biomarkers. By multivariate analysis, both urine NGAL and IL-18 on day 0 predicted the trend in serum creatinine in the posttransplant period after adjusting for effects of age, gender, race, urine output and cold ischemia time (p < 0.01). Our results indicate that urine NGAL and IL-18 represent early, predictive biomarkers of DGF.

Urinary IL-18 is an early predictive biomarker of acute kidney injury after cardiac surgery

Acute kidney injury (AKI) is a frequent complication of cardiopulmonary bypass (CPB). The lack of early biomarkers for AKI has impaired our ability to intervene in a timely manner. Urinary neutrophil gelatinase-associated lipocalin (NGAL) is recently demonstrated as an early biomarker of AKI after CPB, increasing 25-fold within 2 h and declining 6 h after surgery. In the present study, we tested whether interleukin-18 (IL-18) is a predictive biomarker for AKI in the same group of patients following CPB. Exclusion criteria included pre-existing renal insufficiency and nephrotoxin use. Serial urine samples were analyzed by enzyme-linked immunosorbent assay for IL-18 in 20 patients who developed AKI (defined as a 50% or greater increase in serum creatinine after CPB) and 35 controls (age, race, and gender-matched patients who did not develop AKI after CPB). Using serum creatinine, AKI was detected only 48-72 h after CPB. In contrast, urine IL-18 increased at 4-6 h after CPB, peaked at over 25-fold at 12 h, and remained markedly elevated up to 48 h after CPB. The performance of IL-18 as demonstrated by area under the receiver operating characteristics curve for diagnosis of AKI at 4, 12, and 24 h after CPB was 61, 75, and 73% respectively. Also, on multivariate analysis, both IL-18 and NGAL were independently associated with number of days in AKI among cases. Our results indicate that IL-18 is an early, predictive biomarker of AKI after CPB, and that NGAL and IL-18 are increased in tandem after CPB. The combination of these two biomarkers may allow for the reliable early diagnosis and prognosis of AKI at all times after CPB, much before the rise in serum creatinine.

Effects of a dried Bacillus subtilis culture on egg quality

The effects of a dried Bacillus subtilis culture on the egg qualities of layers were studied. Nine hundred and sixty 25-wk-old Lohmann Brown layers were randomly divided into 5 groups with 192 layers in each group. Layers in group 1 were fed a control diet. The remaining groups received the control diet that contained either 20 mg of zinc bacitracin/kg and 4 mg of colistin sulfate/kg or 500, 1,000, or 1,500 mg of B. subtilis culture/ kg, respectively. The results showed improvements in egg production, feed consumption, and feed conversion (P < 0.05) of layers when 500 mg of B. subtilis culture/kg was added to the diets. The results also showed some special improvements in this group, including increases in eggshell thickness, yolk color, and Haugh unit, and decreases in yolk cholesterol concentration (P < 0.05). However, excessive doses of B. subtilis culture did not improve the performance of layers.

Update on the Pharmacokinetic Aspects of Antiretroviral Agents: Implications in Therapeutic Drug Monitoring

The observed inter-individual variation in antiretroviral pharmacokinetics (PK) that results in a wide range of drug exposures from fixed-dose regimens has led to increasing interest in the clinical use of therapeutic drug monitoring (TDM) to individualize dosing of antiretroviral therapy (ART). The focus of this review is to provide an overview of literature available to support therapeutic drug monitoring among the current classes of antiretrovirals, suggest patient populations that may benefit from TDM and bring forth some of the limitations that may exist for widespread use of TDM in a traditional clinical setting.