Population Pharmacokinetics and Initial Dosage Optimization of Tacrolimus in Pediatric Hematopoietic Stem Cell Transplant Patients.

Background: There is a substantial lack of tacrolimus pharmacokinetic information in pediatric hematopoietic stem cell transplant (HSCT) patients. This study aimed to develop population pharmacokinetics (PopPK) of tacrolimus in pediatric HSCT patients and to devise model-guided dosage regimens. Methods: A retrospective analysis was performed on 86 pediatric HSCT patients who received tacrolimus intravenously or orally. A total of 578 tacrolimus trough concentrations (C0) were available for pharmacokinetic analysis using a non-linear mixed-effects modeling method. Demographic and clinical data were included and assessed as covariates via the stepwise method. Bayesian estimators were used to devise pediatric dosage regimens that targeted C0 of 5-15 ng mL-1. Results: A one-compartment model with first-order absorption adequately described the tacrolimus pharmacokinetics. Clearance (CL), volume of distribution (V), and typical bioavailability (F) in this study were estimated to be 2.42 L h-1 (10.84%), 79.6 L (16.51%), and 19% (13.01%), respectively. Body weight, hematocrit, post-transplantation days, and caspofungin and azoles concomitant therapy were considered significant covariates for tacrolimus CL. Hematocrit had a significant impact on the V of tacrolimus. In the subgroup cohort of children (n = 24) with CYP3A5 genotype, the clearance was 1.38-fold higher in CYP3A5 expressers than in non-expressers. Simulation indicated that the initial dosage optimation of tacrolimus for intravenous and oral administration was recommended as 0.025 and 0.1 mg kg-1 d-1 (q12h), respectively. Conclusion: A PopPK model for tacrolimus in pediatric HSCT patients was developed, showing good predictive performance. Model-devised dosage regimens with trough tacrolimus concentrations provide a practical strategy for achieving the therapeutic range.

P-21-activated kinase 1 contributes to tumor angiogenesis upon photodynamic therapy via the HIF-1α/VEGF pathway.

Photodynamic therapy (PDT) is an effective oncotherapy and has been approved for clinical application. Unfortunately, its therapeutic efficacy is usually overshadowed by tumor angiogenesis. Thus, a detailed understanding of the tumor angiogenesis upon PDT is imperative. This study aimed to investigate the potential contribution and mechanism of P-21-activated kinase 1 (PAK1) in PDT-induced tumor angiogenesis. Firstly, we found that PAK1 was upregulated upon PDT and associated with tumor angiogenesis. Then, we elucidated the underlying molecular mechanism. Activation of PAK1 prevents hypoxia-inducible factor 1 alpha (HIF-1α) protein from ubiquitin-mediated degradation. Thereafter, HIF-1α accumulation results in the upregulation of vascular endothelial growth factor (VEGF), thus promoting tumor angiogenesis. More importantly, we determined that PAK1 knockdown effectually repressed tumor angiogenesis, which contributes to enhance the therapeutic effect of PDT. Together, PAK1 is a potential novel pharmaceutical target for inhibiting PDT-induced tumor angiogenesis, and PAK1 suppression in combination with PDT may be a potentially effective strategy for anti-tumor therapy.

The IL-37-Mex3B-Toll-like receptor 3 axis in epithelial cells in patients with eosinophilic chronic rhinosinusitis with nasal polyps.

BACKGROUND: The role of IL-37, an immunosuppressive cytokine, in patients with inflammatory diseases is unclear. OBJECTIVE: We sought to explore the expression and pathogenic function of IL-37 in patients with chronic rhinosinusitis (CRS). METHODS: Expression levels of IL-37, IL-18 receptor α, IL-1 receptor 8, Mex3 RNA binding family member B (Mex3B), and thymic stromal lymphopoietin (TSLP) in nasal samples were studied by using quantitative RT-PCR, immunohistochemistry, Western blotting, and ELISA. Human nasal epithelial cells (HNECs) and the BEAS-2B cell line were stimulated with various cytokines and Toll-like receptor (TLR) agonists. In some experiments BEAS-2B cells were transfected with Mex3B small interfering RNA or overexpressing lentiviruses. Genes regulated by IL-37b in HNECs were studied by using RNA sequencing analysis. IL-37b function was confirmed in mice in vivo. RESULTS: Compared with control subjects, although mRNA and protein expression of IL-37 were upregulated in diseased tissues, especially in nasal epithelial cells, in patients with CRS without nasal polyps or in patients with chronic rhinosinusitis with nasal polyps (CRSwNP), IL-37 levels in nasal secretions were reduced in patients with eosinophilic CRSwNP. Type 2 cytokines inhibited IL-37 secretion from HNECs. HNECs expressed IL-37 receptors, IL-18 receptor α, and IL-1 receptor 8. IL-37b downregulated the expression of Mex3B, a TLR3 coreceptor, in HNECs. IL-37b suppressed polyinosinic-polycytidylic acid-induced TSLP production in HNECs in vitro and in murine nasal epithelial cells in vivo. Knocking down or overexpressing Mex3B in BEAS-2B cells abolished the inhibitory effect of IL-37b. Secreted IL-37 levels negatively correlated with Mex3B and TSLP levels and eosinophil numbers in patients with eosinophilic CRSwNP. CONCLUSIONS: The suppressed IL-37 secretion caused by a type 2 milieu can enhance Mex3B-mediated TLR3 activation and subsequent TSLP production in nasal epithelial cells and therefore promotes eosinophilic inflammation in patients with CRSwNP.

Higd1a Protects Cells from Lipotoxicity under High-Fat Exposure.

Hypoxia-inducible gene domain family member 1A (Higd1a) has recently been reported to protect cells from hypoxia by helping to maintain normal mitochondrial function. The potential induction of Higd1a under high-fat exposure and whether it could protect cells from oxidative stress attracted our attention. Initially, 0.4 mM oleic acid and 0.2 mM palmitate were added to the growth media of HepG2 and LO2 cells for 72 hours. We discovered increased Higd1a expression, and knocking down Higd1a impaired mitochondrial transmembrane potential and induced cell apoptosis. We then identified that elevated reactive oxygen species (ROS) is responsible for increased Higd1a expression. Furthermore, we found that ROS promoted Higd1a expression by upregulating HIF-1a and PGC-1a expressions, and these two proteins could exert synergistic effects in inducing Higd1a expression. Taken together, these data suggest that Higd1a plays positive roles in protecting cells from oxidative stress, and ROS could induce Higd1a expression by upregulating PGC-1a and HIF-1a expressions.

Semiconductor Sequencing Analysis of Chromosomal Copy Number Variations in Spontaneous Miscarriage.

BACKGROUND Array CGH is the criterion standard for identifying copy number variations (CNV), but the restrictive requirement of DNA quality and relatively high cost prevent the use of this method as a general assay in hospitals in developing countries. Our principal objective was to determine whether the semiconductor sequencing platform (SSP) could be an alternative method in CNV detection for spontaneous miscarriage. MATERIAL AND METHODS A total of 443 spontaneous miscarriage samples were collected and subjected to low-coverage (0.1X) whole-genome analysis by SSP. These samples were verified by array CGH and 8 low-quality DNA samples were analyzed by SSP and validated by MLPA. RESULTS SSP detected 195 chromosomal numerical abnormalities, 74 CNVs, and 9 mosaicisms among the 435 samples. Among 74 CNV abnormalities, SSP detected an equal number (56) of CNVs 56 >1 Mb with array CGH. However, SSP missed more 6 cases CNVs <1 Mb than array CGH (12 vs. 18). SSP detected more mosaicisms than array CGH (9 vs. 7, p=0.5). Interestingly, SSP detected the mosaicism which had only 8% X monosomy, which was much lower than the minimal percentage of monosomy that was detected by array CGH. CONCLUSIONS SSP is of equivalent efficacy as array CGH in detecting CNVs >1 Mb, and performs better in identifying mosaicism. With the merits of low cost and less demand of input DNA, SSP is a good alternative for use in genetic diagnosis.

Captopril pretreatment protects the lung against severe acute pancreatitis induced injury via inhibiting angiotensin II production and suppressing Rho/ROCK pathway.

Acute pancreatitis (AP) usually causes acute lung injury, which is also known as acute pancreatitis associated lung injury (APALI). This study aimed to investigate whether captopril pretreatment was able to protect lung against APALI via inhibiting angiotensin II (Ang II) production and suppressing Rho/ROCK (Rho kinase) pathway in rats. Severe AP (SAP) was introduced to rats by bile-pancreatic duct retrograde injection of 5% sodium taurocholate. Rats were randomly divided into three groups. In the sham group, sham operation was performed; in the SAP group, SAP was introduced; in the pre-cpl + SAP group, rats were intragastrically injected with 5 mg/kg captopril 1 hour prior to SAP induction. Pathological examination of the lung and pancreas, evaluation of pulmonary vascular permeability by wet/dry ratio and Evans Blue staining, detection of serum amylase, Western blot assay for Ang II receptor type 1 (AT1), RhoA, ROCK (Rho kinase), and MLCK (myosin light chain kinase) were performed after the animals were sacrificed at 24 hours. After the surgery, characteristic findings of pancreatitis were observed, accompanied by lung injury. The serum amylase, Ang II, and lung expression of AT1, RhoA, ROCK, and MLCK increased dramatically in SAP rats. However, captopril pretreatment improved the histological changes, reduced the pathological score of the pancreas and lung, inhibited serum amylase and Ang II production, and decreased expression of AT1, RhoA, ROCK, and MLCK in the lung. These findings suggest that captopril pretreatment is able to protect the lung against APALI, which is, at least partially, related to the inhibition of Ang II production and the suppression of the Rho/ROCK pathway.

Hyperbaric oxygen preconditioning protects the lung against acute pancreatitis induced injury via attenuating inflammation and oxidative stress in a nitric oxide dependent manner.

This study aimed to investigate the protective effects of hyperbaric oxygen preconditioning (HBO-PC) on acute pancreatitis AP associated acute lung injury (ALI) and the potential mechanisms. Rats were randomly divided into sham group, AP group, HBO-PC + AP group and HBO-PC + L-NAME group. Rats in HBO-PC + AP group received HBO-PC once daily for 3 days, and AP was introduced 24 h after last HBO-PC. In HBO-PC + L-NAME group, L-NAME (40 mg/kg) was intraperitoneally injected before each HBO-PC. At 24 h after AP, the blood lipase and amylase activities were measured; the lung and pancreas were harvested for pathological examination; the bronchoalveolar lavage fluid was collected for the detection of lactate dehydrogenase (LDH) and proteins; inflammatory factors, superoxide dismutase (SOD) activity and malonaldehyde content were measured in the lung and blood; the Nrf2, SOD-1 and haem oxygenase-1 (HO-1) protein expression was measured in the lung. The lung nitric oxide (NO) and NO synthase activity increased significantly after HBO-PC. HBO-PC was able to reduce blood lipase and amylase activities, improve lung and pancreatic pathology, decrease LDH and proteins in BALF, inhibit the production of inflammatory factors, reduce malonaldehyde content and increase SOD activity in the lung and blood as well as increase protein expression of Nrf2, SOD-1 and HO-1 in the lung. However, L-NAME before HBO-PC significantly attenuated protective effects of HBO-PC. HBO-PC is able to protect the lung against AP induced injury by attenuating inflammation and oxidative stress in the lung via a NO dependent manner.

Advances in genetic studies of inherited bone marrow failure syndromes and their associated malignancies.

The inherited bone marrow failure syndromes (IBMFS) are a rare group of heterogeneous genetic disorders characterised by bone marrow failure, commonly associated with one or more congenital anomalies found in patients which have a familiar predisposition. Genetic detection of IBMFS disease types is not only to benefit to affected patients but also of help to relatives unaffected phenotypically. Patients with IBMFS have a high risk of hematologic malignancies, commonly myelodyspastic syndrome (MDS), acute myeloid leukemia (AML) and specific types solid tumours. These malignancies may require different treatment strategies due to the underlying gene defects. Studies demonstrate that over 40 genes mutations are associated with IBMFS. Recently studies using next generation sequencing have increased our understanding of the etiology and classification of IBMFS, particularly the link between the defects and the biological mechanism leading to malignancies.

Chronic restraint stress aggravated arthritic joint swell of rats through regulating nitric oxide production.

Stress-related hormone norepinephrine (NE) displayed diverse effects on immune system including macrophages, which influenced many kinds of inflammatory diseases. Nitric oxide (NO) from activated macrophages played an important role in inflammatory diseases. In this study, we investigated under chronic restraint stress how NE influenced the joint swell of Complete Freund's Adjuvant (CFA)-induced arthritis of rats and whether NE regulated macrophage's production of NO through influencing phosphorylation of protein kinases C (PKC). The results showed chronic restraint stress exacerbated paw swell of rats with arthritis. Inhibitor of inducible nitric oxide synthase, S-methylisothiourea (SMT), and 6-hydroxydopamine (6-OHDA) could counteract the effect of restraint stress on arthritis. NE, NO and endotoxin in plasma of rats underwent restraint were improved significantly. In vitro experiments, NE could promote macrophage to produce more NO and iNOS when macrophage was activated by lipopolysaccharide (LPS). This effect could be inhibited by α adrenergic antagonist phentolamine. Nevertheless, through α receptor NE could promote the phosphorylation of PKC and PKC inhibitor staurosporine could counteract NE's enhancive effect on production of NO and iNOS of macrophages. This study revealed that NE could exacerbate arthritic joint swell through promoting NO production, which was in α receptor dependent way through enhancing phosphorylation of PKC for NE to enhance the iNOS expression of activated macrophage.

Development of a multiplex quantitative fluorescent PCR assay for identification of rearrangements in the AZFb and AZFc regions.

The azoospermia factor b (AZFb) and azoospermia factor c (AZFc) regions in the human Y chromosome consist of five palindromes constructed from six distinct families of amplicons and are prone to rearrangement. Partial deletion and duplication in the region can cause azoospermia or oligozoospermia and male infertility. The aim of the study was to establish a quantitative fluorescent PCR (QF-PCR) assay to classify AZFb and AZFc rearrangements. A single pair of fluorescent primers was designed to amplify simultaneously the amplicon in AZFc and the length-variant homologous sequences outside of the region as control. Since the copy number of the control sequences is fixed in the human genome, dosage of the target could be easily obtained through comparing the height of the fluorescent peaks between the target and the control after amplification with limited PCR cycles. Most types of rearrangements in AZFb and AZFc regions could be classified with QF-PCR containing four such primer pairs. Eleven types of rearrangement in AZFb and AZFc regions were well discriminated with QF-PCR. In conclusion, QF-PCR is a simple and reliable method to detect rearrangements in AZFb and AZFc.