Na+ riboswitches regulate genes for diverse physiological processes in bacteria.

Organisms presumably have mechanisms to monitor and physiologically adapt to changes in cellular Na+ concentrations. Only a single bacterial protein has previously been demonstrated to selectively sense Na+ and regulate gene expression. Here we report a riboswitch class, previously called the 'DUF1646 motif', whose members selectively sense Na+ and regulate the expression of genes relevant to sodium biology. Many proteins encoded by Na+-riboswitch-regulated genes are annotated as metal ion transporters, whereas others are involved in mitigating osmotic stress or harnessing Na+ gradients for ATP production. Na+ riboswitches exhibit dissociation constants in the low mM range, and strongly reject all other alkali and alkaline earth ions. Likewise, only Na+ triggers riboswitch-mediated transcription and gene expression changes. These findings reveal that some bacteria use Na+ riboswitches to monitor, adjust and exploit Na+ concentrations and gradients, and in some instances collaborate with c-di-AMP riboswitches to coordinate gene expression during osmotic stress.

A targeted antibody-based array reveals a serum protein signature as biomarker for adolescent idiopathic scoliosis patients.

BACKGROUND: Evident adolescent idiopathic scoliosis (AIS) incurs high treatment costs, low quality of life, and many complications. Early screening of AIS is essential to avoid progressing to an evident stage. However, there is no valid serum biomarker for AIS for early screening. METHODS: Antibody-based array is a large-scale study of proteins, which is expected to reveal a serum protein signature as biomarker for AIS. There are two segments of the research, including biomarkers screening and validation. In the biomarkers screening group, a total of 16 volunteers participated in this study, and we carried out differentially expressed proteins screening via protein array assay between No-AIS group and the AIS group, through which GeneSet enrichment analysis was performed. In the validation group with a total of 62 volunteers, the differentially expressed proteins from screening group were verified by Enzyme-Linked immunosorbent assay (ELISA), and then multiple regression analysis. RESULTS: In our study, there were twenty-nine differentially expressed proteins in AIS, through Protein array assay and GeneSet enrichment analysis in the biomarkers screening group. Then the expression of FAP, CD23 and B2M decreased as the degree of AIS increased via ELISA in validation group (FAP, p < 0.0001; CD23, p = 0.0002; B2M, p < 0.0001). Further, the results of multiple regression analysis showed that FAP, CD23 are linked to Cobb angle, whereas B2M were excluded because of multicollinearity. CONCLUSIONS: Altogether, we found that serum protein FAP and CD23 are intimately related to AIS, suggesting FAP and CD23 are expected to serve as the serum biomarkers, which significantly facilitate frequent longitudinal monitoring as to keep track of disease progression and tailor treatment accordingly.

Association of polymorphisms in the IL-10 promoter region with Crohn's disease.

BACKGROUND: IL-10 is thought to play an important role in preventing inflammatory bowel disease (IBD), although its efficacy is limited in IBD inflammation treatment. The purpose of this study is to investigate the association between SNP polymorphism in the promoter region of the IL-10 gene and Crohn's disease (CD). METHODS: In 86 children with CD disease and 142 healthy controls, polymorphisms of three SNPs (rs3790622, rs1800872, and rs1800896) in the IL-10 promoter region were successfully identified. The risk alleles, genotypes, and haplotypes were also analyzed in the CD patient group and the control group. 2 × 2 chi-square test was used to identify whether there is a statistically significant association between CD risk and SNP polymorphisms. RESULTS: According to the chi-square test results, only the polymorphism of rs1800872 was associated with pediatric CD. T allele in rs1800872 showed a high risk for pediatric CD (Pearson χ2 p = 0.030). TT genotype of rs1800872 was associated with a higher risk of CD in the pediatric population (OR 1.986, 95% CI 1.146-3.442, p = 0.020, TT vs. TG + GG). Finally, a risk haplotype GTT (rs3790622-rs1800872-rs1800896) in IL-10 was found (OR 1.570, 95% CI 1.054-2.341, p = 0.028). CONCLUSIONS: Our data suggested that T allele, TT genotype, and haplotype GTT in rs1800872 were associated with the susceptibility to pediatric CD in China.

The phosphodiesterase-4 inhibitor rolipram attenuates heroin-seeking behavior induced by cues or heroin priming in rats.

Inhibition of phosphodiesterase-4 (PDE4), an enzyme that specifically hydrolyzes cyclic adenosine monophosphate (cAMP) increases intracellular cAMP/cAMP-response element binding protein (CREB) signaling. Activation of this signaling is considered as an important compensatory response that decreases motivational properties of drugs of abuse. However, it is not known whether PDE4 is involved in heroin seeking. Self-administration of heroin (50 µg/kg/infusion) was performed under the fixed ratio 1 (FR1) schedule for 14 d and then drug seeking was extinguished for 10 d. The progressive ratio schedule was used to evaluate the relative motivational value of heroin reinforcement. After training, the conditioned cue or heroin priming (250 µg/kg) was introduced for the reinstatement of heroin-seeking behavior. Pretreatment (i.p.) with rolipram (0.03-0.3 mg/kg), a prototypical, selective PDE4 inhibitor, failed to inhibit heroin self-administration under the FR1 schedule, but decreased the reward values under the progressive ratio schedule in a dose-dependent manner. In addition, rolipram decreased the reinstatement of heroin seeking induced by cues or heroin priming even at the lowest dose (0.03 mg/kg); in contrast, the highest dose (0.3 mg/kg) of rolipram was required to decrease sucrose reinforcement. Finally, the effects of rolipram on heroin-seeking behavior were correlated with the increases in expression of phosphorylated CREB in the nucleus accumbens. The study demonstrated that rolipram inhibited heroin reward and heroin-seeking behavior. The results suggest that PDE4 plays an essential role in mediating heroin seeking and that PDE4 inhibitors may be used as a potential pharmacotherapeutic approach for heroin addiction.

Sample size determination for equivalence assessment with multiple endpoints.

Equivalence assessment between a reference and test treatment is often conducted by two one-sided tests (TOST). The corresponding power function and sample size determination can be derived from a joint distribution of the sample mean and sample variance. When an equivalence trial is designed with multiple endpoints, it often involves several sets of two one-sided tests. A naive approach for sample size determination in this case would select the largest sample size required for each endpoint. However, such a method ignores the correlation among endpoints. With the objective to reject all endpoints and when the endpoints are uncorrelated, the power function is the production of all power functions for individual endpoints. With correlated endpoints, the sample size and power should be adjusted for such a correlation. In this article, we propose the exact power function for the equivalence test with multiple endpoints adjusted for correlation under both crossover and parallel designs. We further discuss the differences in sample size for the naive method without and with correlation adjusted methods and illustrate with an in vivo bioequivalence crossover study with area under the curve (AUC) and maximum concentration (Cmax) as the two endpoints.

Associations Between Neuroinflammation-Related Conditions and Alzheimer's Disease: A Study of US Insurance Claims Data.

Background: Early detection of Alzheimer's disease (AD) is a key component for the success of the recently approved lecanemab and aducanumab. Patients with neuroinflammation-related conditions are associated with a higher risk for developing AD. Objective: Investigate the incidence of AD among patients with neuroinflammation-related conditions including epilepsy, hemorrhage stroke, multiple sclerosis (MS), and traumatic brain injury (TBI). Methods: We used Optum's de-identified Clinformatics Data Mart Database (CDM). We derived covariate-matched cohorts including patients with neuroinflammation-related conditions and controls without the corresponding condition. The matched cohorts were: 1) patients with epilepsy and controls (N = 67,825 matched pairs); 2) patients with hemorrhage stroke and controls (N = 81,510 matched pairs); 3) patients with MS and controls (N = 9,853 matched pairs); and 4) patients TBI and controls (N = 104,637 matched pairs). We used the Cox model to investigate the associations between neuroinflammation-related conditions and AD. Results: We identified that epilepsy, hemorrhage stroke, and TBI were associated with increased risks of AD in both males and females (hazard ratios [HRs]≥1.74, p < 0.001), as well as in gender- and race-conscious subpopulations (HRs≥1.64, p < 0.001). We identified that MS was associated with increased risks of AD in both males and females (HRs≥1.47, p≤0.004), while gender- and race-conscious subgroup analysis shown mixed associations. Conclusions: Patients with epilepsy, hemorrhage stroke, MS, and/or TBI are associated with a higher risk of developing AD. More attention on cognitive status should be given to older patients with these conditions.

Understanding Patterns of Preserved Retinal Ganglion Cell Layer in Advanced Glaucoma as seen with OCT.

PRECIS: Using OCT, eyes with advanced glaucoma were found to have a wide range of patterns of damage that were consistent with the natural history of progression based upon a model of macular progression. PURPOSE: To understand the patterns of preserved retinal ganglion cells in eyes with advanced glaucoma using OCT and a model of progression of the central macula. METHODS: OCT GCL thickness was measured in 94 eyes with advanced glaucoma, defined as glaucomatous eyes with a 24-2 MD (mean deviation) worse than -12 dB. A commercial report supplied the GCL thickness in 6 sectors of the thick, donut-shaped GCL region around the fovea. For each eye, the 6 sectors were coded as green (within normal limits, WNL), yellow (≤5th, ≥1st percentile), or red (<1st percentile). RESULTS: In all 94 eyes, one or more of the 6 sectors of the donut were abnormal (red or yellow), while all 6 sectors were red in 52 (55%) of the eyes. On the other hand, 33 eyes had one or more sectors WNL (green). While the pattern of donut damage varied widely across these 33 eyes, 61 of the 66 hemiretinas were consistent with a temporal-to-nasal progression of damage within each hemiretina as predicted by our model. CONCLUSION: All eyes with advanced glaucoma had damage to the critically important central, donut-shaped GCL region. This region showed a wide range of patterns of damage, but these patterns were consistent with the natural history of progression based upon a model of macular progression. These results have implications for the clinical identification of macular progression, as well as for inclusion criteria for clinical trials seeking to preserve central macular function.

Application of an Innovative Data Mining Approach Towards Safe Polypharmacy Practice in Older Adults.

INTRODUCTION: Polypharmacy is common and is associated with higher risk of adverse drug event (ADE) among older adults. Knowledge on the ADE risk level of exposure to different drug combinations is critical for safe polypharmacy practice, while approaches for this type of knowledge discovery are limited. The objective of this study was to apply an innovative data mining approach to discover high-risk and alternative low-risk high-order drug combinations (e.g., three- and four-drug combinations). METHODS: A cohort of older adults (≥ 65 years) who visited an emergency department (ED) were identified from Medicare fee-for-service and MarketScan Medicare supplemental data. We used International Classification of Diseases (ICD) codes to identify ADE cases potentially induced by anticoagulants, antidiabetic drugs, and opioids from ED visit records. We assessed drug exposure data during a 30-day window prior to the ED visit dates. We investigated relationships between exposure of drug combinations and ADEs under the case-control setting. We applied the mixture drug-count response model to identify high-order drug combinations associated with an increased risk of ADE. We conducted therapeutic class-based mining to reveal low-risk alternative drug combinations for high-order drug combinations associated with an increased risk of ADE. RESULTS: We investigated frequent high-order drug combinations from 8.4 million ED visit records (5.1 million from Medicare data and 3.3 million from MarketScan data). We identified 5213 high-order drug combinations associated with an increased risk of ADE by controlling the false discovery rate at 0.01. We identified 1904 high-order, high-risk drug combinations had potential low-risk alternative drug combinations, where each high-order, high-risk drug combination and its corresponding low-risk alternative drug combination(s) have similar therapeutic classes. CONCLUSIONS: We demonstrated the application of a data mining technique to discover high-order drug combinations associated with an increased risk of ADE. We identified high-risk, high-order drug combinations often have low-risk alternative drug combinations in similar therapeutic classes.

Sample size of thorough QTc clinical trial adjusted for multiple comparisons.

A thorough QT trial is typically designed to test for two sets of hypotheses. The primary set of hypotheses is for demonstrating that the test treatment will not prolong QT interval. The second set of hypotheses is to demonstrate the assay sensitivity of the positive control treatment in the study population. Both analyses require multiple comparisons by testing the treatment difference measured repeatedly at multiple selected time points. Tsong and Zhong (2010) indicated that for prolongation testing, this involves an intersection-union test that leads to the reduction of study power. It requires type II error rate adjustment in order to maintain proper sample size and power of the test. Tsong et al. (2010) indicated also that the assay sensitivity analysis is carried out using a union-intersection test that leads to the inflation of the family-wise type I error rate. Type I error rate adjustment is required to control the family-wise type I error rate. Zhang and Machado (2008) proposed the sample size calculation of test-placebo QT response difference based on simulation with a multivariate normal distribution model. Even though the results are generally used as guidance for sample size determination for balanced arm TQT trials, they are limited in generalization to various advanced and adaptive designs of TQT trials (Zhang, 2011 ; Tsong, 2013). In this article, we propose a power equation based on multivariate normal distribution of TQT trials. Sample sizes of various TQT designs can be obtained through numerical iteration of the equation.

An Early Adverse Drug Event Detection Approach with False Discovery Rate Control.

Adverse drug event (ADE) is a significant challenge in clinical practice. Many ADEs have not been identified timely after the approval of the corresponding drugs. Despite the use of drug similarity network demonstrates early success on improving ADE detection, false discovery rate (FDR) control remains unclear in its application. Additionally, performance of early ADE detection has not been explicitly investigated under the time-to-event framework. In this manuscript, we propose to use the drug similarity based posterior probability of null hypothesis for early ADE detection. The proposed approach is also able to control FDR for monitoring a large number of ADEs of multiple drugs. The proposed approach outperforms existing approaches on mining labeled ADEs in the US FDA's Adverse Event Reporting System (FAERS) data, especially in the first few years after the drug initial reporting time. Additionally, the proposed approach is able to identify more labeled ADEs and has significantly lower time to ADE detection. In simulation study, the proposed approach demonstrates proper FDR control, as well as has better true positive rate and an excellent true negative rate. In our exemplified FAERS analysis, the proposed approach detects new ADE signals and identifies ADE signals in a timelier fashion than existing approach. In conclusion, the proposed approach is able to both reduce the time and improve the FDR control for ADE detection.

Is depression in patients with temporal lobe epilepsy related to hippocampal sclerosis? A meta-analysis.

OBJECTIVE: To systematically evaluate the association between hippocampal sclerosis (HS) and depression in patients with temporal lobe epilepsy (TLE) through a meta-analysis. METHODS: Chinese and English databases, such as the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP), WanFang, the Chinese Biomedical Literature Service System (SinoMed), PubMed and the Web of Science, were searched. RESULTS: Two evaluators independently screened the literature, extracted data and evaluated the risk of bias in the included studies in accordance with the inclusion and exclusion criteria. RevMan 5.1 was used to analyze the data. A total of 786 patients with epilepsy were included in the study, including 82 depressive patients with HS and 64 depressive patients without HS. The results showed that the TLE patients with HS were more likely to develop depression than those without HS (odds ratio (OR)= 2.14, 95% confidence interval (CI) [1.45, 3.16], Z = 3.85, p = 0.0001). CONCLUSION: HS can be considered a high-risk factor for depression in patients with TLE, and the correlation is significant. However, the sample size included in the study was small; additional high-quality studies are needed in the future.

Association of Catalase Gene Polymorphisms with Idiopathic Nephrotic Syndrome in a Chinese Pediatric Population.

OBJECTIVE: Our aim was to investigate the association between gene polymorphisms in catalase (CAT), a well-known oxidative stress regulator, and susceptibility to idiopathic nephrotic syndrome (INS) or responses to steroid therapy in a Chinese pediatric population. METHODS: We analyzed 3 CAT single-nucleotide polymorphisms (SNVs; rs7943316, rs769217, and rs12270780) using multi-polymerase chain reaction combined with next-generation sequencing in 183 INS patients and 100 healthy controls. RESULTS: For the allele and genotype frequencies of the CAT SNVs, no significant differences were observed between INS patients and controls. Patients with C allele of CAT rs769217 had a higher risk of developing steroid-dependent nephrotic syndrome than the steroid-sensitive nephrotic syndrome patients (P = 0.018; odds ratio = 1.76). CONCLUSION: Our data suggests that genetic variations in CAT were unlikely to confer susceptibility to INS in Chinese children, whereas the C allele of the CAT rs769217 polymorphism showed a strong association with steroid-dependent responses in Chinese INS children.

Lithium-sensing riboswitch classes regulate expression of bacterial cation transporter genes.

Lithium is rare in Earth's crust compared to the biologically relevant alkali metal cations sodium and potassium but can accumulate to toxic levels in some environments. We report the experimental validation of two distinct bacterial riboswitch classes that selectively activate gene expression in response to elevated Li+ concentrations. These RNAs commonly regulate the expression of nhaA genes coding for ion transporters that weakly discriminate between Na+ and Li+. Our findings demonstrated that the primary function of Li+ riboswitches and associated NhaA transporters is to prevent Li+ toxicity, particularly when bacteria are living at high pH. Additional riboswitch-associated genes revealed how some cells defend against the deleterious effects of Li+ in the biosphere, which might become more problematic as its industrial applications increase.

Tumor-educated CD11bhighIalow regulatory dendritic cells suppress T cell response through arginase I.

Tumors can induce generation and accumulation of the immunosuppressive cells such as regulatory T cells in the tumor microenvironment, contributing to tumor escape from immunological attack. Although dendritic cell (DC)-based cancer vaccine can initiate antitumor immune response, regulatory DC subsets involved in the tolerance induction attracted much attention recently. Our previous studies demonstrate that the stromal microenvironment of the spleen, lung, and liver can program generation of CD11c(low)CD11b(high)Ia(low) DCs with regulatory function (CD11b(high)Ia(low) regulatory DCs). However, whether and how the tumor microenvironment can program generation of CD11b(high)Ia(low) regulatory DCs remain to be investigated. In this study, we used the freshly isolated tumor cells to mimic tumor microenvironment to coculture DCs and found that the freshly isolated tumor cells could drive DCs to differentiate into regulatory DCs with a CD11c(low)CD11b(high)Ia(low) phenotype and high expression of IL-10, NO, vascular endothelial growth factor, and arginase I. Tumor-educated CD11b(high)Ia(low) regulatory DCs inhibited CD4(+) T cell proliferation both in vitro and in vivo. 3LL lung cancer-derived TGF-beta and PGE(2) were responsible for the generation of regulatory DCs. PGE(2) was the main inducer of arginase I in regulatory DCs. Arginase I played a major role in the suppression of T cell response by regulatory DCs induced by 3LL lung cancer. A natural counterpart of CD11b(high)Ia(low) DCs was identified in tumor tissue, and CD11b(high)Ia(low) DCs sorted from 3LL lung cancer tissue expressed arginase I and inhibited T cell response. Therefore, tumors can educate DCs to differentiate into a regulatory DC subset, which contributes to constitution of the immunosuppressive tumor microenvironment and promotes tumor immune escape.

Gene-by-environment modulation of lifespan and weight gain in the murine BXD family.

How lifespan and body weight vary as a function of diet and genetic differences is not well understood. Here we quantify the impact of differences in diet on lifespan in a genetically diverse family of female mice, split into matched isogenic cohorts fed a low-fat chow diet (CD, n = 663) or a high-fat diet (HFD, n = 685). We further generate key metabolic data in a parallel cohort euthanized at four time points. HFD feeding shortens lifespan by 12%: equivalent to a decade in humans. Initial body weight and early weight gains account for longevity differences of roughly 4-6 days per gram. At 500 days, animals on a HFD typically gain four times as much weight as control, but variation in weight gain does not correlate with lifespan. Classic serum metabolites, often regarded as health biomarkers, are not necessarily strong predictors of longevity. Our data indicate that responses to a HFD are substantially modulated by gene-by-environment interactions, highlighting the importance of genetic variation in making accurate individualized dietary recommendations.

Diagnostic Yield of Pneumococcal Antigen Detection in Cerebrospinal Fluid for Diagnosis of Pneumococcal Meningitis Among Children in China.

OBJECTIVE: To determine the diagnostic accuracy of pneumococcal antigen detection in diagnosis of pneumococcal meningitis in children. METHODS: Purulent meningitis was diagnosed according to European Society for Clinical Microbiology and Infectious Diseases (ESCMID) guideline between July 2014 and June 2016. Along with a cerebrospinal fluid (CSF) culture, pneumococcal antigen detection in cerebrospinal fluid (CSF) was performed, and further identification of pathogens was done with 16S rDNA-PCR and high-throughput sequencing. RESULTS: CSF samples collected from 184 children (median age of 1.92 mo). CSF culture was used as the gold standard. 46 (25%) had positive results for culture and 10 (5.4%) were pneumococci; 34 (18.5%) were pneumococcal antigen positive. The sensitivity and specificity of pneumococcal antigen detection were 100% (95% CI: 89.4%-100%) and 86.2% (95% CI: 96.4%-99.9%), respectively. 92.3% (12/13) were confirmed by nucleic acid detection to be pneumococci. CONCLUSIONS: Pneumococcal antigen detection in CSF has adequate sensitivity and specificity in diagnosing pneumococcal meningitis.

Plant-derived small molecule albaconol suppresses LPS-triggered proinflammatory cytokine production and antigen presentation of dendritic cells by impairing NF-kappaB activation.

Dendritic cells (DCs) play crucial roles in linking innate immunity and adaptive immunity, thus being regarded as one of the important targets of immunosuppressant. Natural small molecule products isolated from plants, such as fungal metabolites, have been shown to be effective in the treatment of cancer, inflammation and autoimmune diseases. Albaconol is a new kind of prenylated resorcinols isolated from the fruiting bodies of the inedible mushroom Albatrellus confluens, and has been shown to inhibit tumor cell growth. Considering that most of small molecule compounds with antitumor activity always exert immunosuppressive effect, so we wonder whether albaconol could inhibit maturation and antigen presentation of DCs, thus acting as immunosuppressant. Here we demonstrate that albaconol significantly inhibits LPS-induced production of proinflammatory cytokines TNF-alpha, IL-6, IL-1beta, and expression of MHC-II and co-stimulatory molecules by DCs. Furthermore, albaconol markedly inhibits T cell-stimulating capacity of DCs and DCs-initiated antigen-specific T cell response, indicating albaconol can inhibit phenotypic and functional maturation of DCs. Inhibition of LPS-induced NF-kappaB activation may contribute to the above immunosuppressive or anti-inflammatory activities of albaconol. Therefore, our results suggest that natural small molecule albaconol may be a potential immunosuppressive and anti-inflammatory agent through suppressing DCs function via impairment of NF-kappaB activation.

Albaconol, a plant-derived small molecule, inhibits macrophage function by suppressing NF-kappaB activation and enhancing SOCS1 expression.

Discovery and functional identification of plant-derived small compounds as the immunosuppressant attract much attention these years. Albaconol is a new kind of small compound, prenylated resorcinol, isolated from the fruiting bodies of the inedible mushroom Albatrellus confluens. Our previous studies showed that albaconol can inhibit tumor cell growth and dendritic cell maturation. However, the immunomodulatory roles and the underlying mechanisms of albaconol have not been fully understood. In this study we investigated the effects of albaconol on the proliferation and LPS-induced proinflammatory cytokine production of macrophages. Albaconol, when used at a dose higher than 1.0 microg/ml, inhibited proliferation of RAW264.7 cells in a dose- and time-dependent manner, and could induce cellular apoptosis when used at high dosage (>or= 7.5 microg/ml). Furthermore, we found that albaconol used at a lower dosage without apoptosis induction could significantly inhibit LPS-induced TNF-alpha, IL-6, IL-1beta and NO production in RAW264.7 cells. The inhibition of NF-kappaB activation and enhancement of SOCS1 expression in LPS-stimulated macrophages by albaconol may contribute to the above immunosuppressive or anti-inflammatory activities of albaconol. Our results suggest that albaconol may be a potential immunosuppressive and anti-inflammatory drug.

Triptolide impairs dendritic cell migration by inhibiting CCR7 and COX-2 expression through PI3-K/Akt and NF-kappaB pathways.

Inhibition of dendritic cell (DC) migration into tissues and secondary lymphoid organs is an efficient way to induce immunosuppression and tolerance. CCR7 and PGE(2) are critical for DC migration to secondary lymphoid organs where DC initiate immune response. Triptolide, an active component purified from the medicinal plant Tripterygium Wilfordii Hook F., is a potent immunosuppressive drug capable of prolonging allograft survival in organ transplantation by inhibiting T cell activation and proliferation. Considering the essential role in T cell tolerance of DC migration to secondary lymphoid organs, here we demonstrate that triptolide can significantly inhibit LPS-triggered upregulation of CCR7 expression and PGE(2) production by inhibiting cyclooxygenase-2 (COX-2) expression in DC, thus impairing DC migration towards CCR7 ligand CCL19/MIP-3betain vitro. Moreover, triptolide-treated DC display impaired migration into secondary lymphoid organs and in vivo administration of triptolide also inhibits DC migration. Further studies show that the triptolide-mediated inhibitory effects of LPS-induced activation of phosphatidylinositol-3 kinase (PI3-K)/Akt and nuclear NF-kappaB activation are involved in down-regulation of COX-2 and CCR7 expression resulting in impaired migration to secondary lymphoid organs of DC. Therefore, inhibition of DC migration through decreasing COX-2 and CCR7 expression via PI3-K/Akt and NF-kappaB signal pathways provides additional mechanistic explanation for triptolide's immunosuppressive effect.

Synergistic function of Smad4 and PTEN in suppressing forestomach squamous cell carcinoma in the mouse.

The genetic bases underlying esophageal tumorigenesis are poorly understood. Our previous studies have shown that coordinated deletion of the Smad4 and PTEN genes results in accelerated hair loss and skin tumor formation in mice. Herein, we exemplify that the concomitant inactivation of Smad4 and PTEN accelerates spontaneous forestomach carcinogenesis at complete penetrance during the first 2 months of age. All of the forestomach tumors were invasive squamous cell carcinomas (SCCs), which recapitulated the natural history and pathologic features of human esophageal SCCs. A small population of the SCC lesions was accompanied by adenocarcinomas at the adjacent submucosa region in the double mutant mice. The rapid progression of forestomach tumor formation in the Smad4 and PTEN double knockout mice corresponded to a dramatic increase in esophageal and forestomach epithelial proliferation. The decreased expression of p27, p21, and p16 together with the overexpression of cyclin D1 contributed cooperatively to the accelerated forestomach tumorigenesis in the double mutant mice. Our results point strongly to the crucial relevance of synergy between Smad4 and PTEN to suppress forestomach tumorigenesis through the cooperative induction of cell cycle inhibitors.