Targeting glutamine metabolism exhibits anti-tumor effects in thyroid cancer

BACKGROUND

Effective treatment for patients with advanced thyroid cancer is lacking. Metabolism reprogramming is required for cancer to undergo oncogenic transformation and rapid tumorigenic growth. Glutamine is frequently used by cancer cells for active bioenergetic and biosynthetic needs. This study aims to investigate whether targeting glutamine metabolism is a promising therapeutic strategy for thyroid cancer.

METHODS

The expression of glutaminase (GLS) and glutamate dehydrogenase (GDH) in thyroid cancer tissues was evaluated by immunohistochemistry, and glutamine metabolism-related genes were assessed using real time-qPCR and western blotting. The effects of glutamine metabolism inhibitor 6-diazo-5-oxo-l-norleucine (DON) on thyroid cancer cells were determined by CCK-8, clone formation assay, Edu incorporation assay, flow cytometry, and Transwell assay. The mechanistic study was performed by real time-qPCR, western blotting, Seahorse assay, and gas chromatography-mass spectrometer assay. The effect of DON prodrug (JHU-083) on thyroid cancer in vivo was assessed using xenograft tumor models in BALB/c nude mice.

RESULTS

GLS and GDH were over-expressed in thyroid cancer tissues, and GLS expression was positively associated with lymph-node metastasis and TNM stage. The growth of thyroid cancer cells was significantly inhibited when cultured in glutamine-free medium. Targeting glutamine metabolism with DON inhibited the proliferation of thyroid cancer cells. DON treatment did not promote apoptosis, but increased the proportion of cells in the S phase, accompanied by the decreased expression of cyclin-dependent kinase 2 and cyclin A. DON treatment also significantly inhibited the migration and invasion of thyroid cancer cells by reducing the expression of N-cadherin, Vimentin, matrix metalloproteinase-2, and matrix metalloproteinase-9. Non-essential amino acids, including proline, alanine, aspartate, asparagine, and glycine, were reduced in thyroid cancer cells treated with DON, which could explain the decrease of proteins involved in migration, invasion, and cell cycle. The efficacy and safety of DON prodrug (JHU-083) for thyroid cancer treatment were verified in a mouse model. In addition to suppressing the proliferation and metastasis potential of thyroid cancer in vivo, enhanced innate immune response was also observed in JHU-083-treated xenograft tumors as a result of decreased expression of cluster of differentiation 47 and programmed cell death ligand 1.

CONCLUSIONS

Thyroid cancer exhibited enhanced glutamine metabolism, as evidenced by the glutamine dependence of thyroid cancer cells and high expression of multiple glutamine metabolism-related genes. Targeting glutamine metabolism with DON prodrug could be a promising therapeutic option for advanced thyroid cancer.

A large-scale retrospective study enabled deep-learning based pathological assessment of frozen procurement kidney biopsies to predict graft loss and guide organ utilization

Lesion scores on procurement donor biopsies are commonly used to guide organ utilization for deceased-donor kidneys. However, frozen sections present challenges for histological scoring, leading to inter- and intra-observer variability and inappropriate discard. Therefore, we constructed deep-learning based models to recognize kidney tissue compartments in hematoxylin & eosin-stained sections from procurement needle biopsies performed nationwide in years 2011-2020. To do this, we extracted whole-slide abnormality features from 2431 kidneys and correlated with pathologists' scores and transplant outcomes. A Kidney Donor Quality Score (KDQS) was derived and used in combination with recipient demographic and peri-transplant characteristics to predict graft loss or assist organ utilization. The performance on wedge biopsies was additionally evaluated. Our model identified 96% and 91% of normal/sclerotic glomeruli respectively; 94% of arteries/arterial intimal fibrosis; 90% of tubules. Whole-slide features of Sclerotic Glomeruli (GS)%, Arterial Intimal Fibrosis (AIF)%, and Interstitial Space Abnormality (ISA)% demonstrated strong correlations with corresponding pathologists' scores of all 2431 kidneys, but had superior associations with post-transplant estimated glomerular filtration rates in 2033 and graft loss in 1560 kidneys. The combination of KDQS and other factors predicted one- and four-year graft loss in a discovery set of 520 kidneys and a validation set of 1040 kidneys. By using the composite KDQS of 398 discarded kidneys due to "biopsy findings", we suggest that if transplanted, 110 discarded kidneys could have had similar survival to that of other transplanted kidneys. Thus, our composite KDQS and survival prediction models may facilitate risk stratification and organ utilization while potentially reducing unnecessary organ discard.

Higher Cognitive Reserve Is Beneficial for Cognitive Performance Via Various Locus Coeruleus Functional Pathways in the Pre-Dementia Stage of Alzheimer's Disease

BACKGROUND

Cognitive reserve (CR) shows protective effects on cognitive function in older adult and in Alzheimer's disease (AD). However, the brain mechanisms underlying the CR effect on the non-dementia AD spectrum (subjective cognitive decline (SCD) and mild cognitive impairment (MCI)) are unknown. The aim of this study was to investigate the potential moderate effect of CR on brain functional networks associated with cognitive performance.

METHODS

We selected 200 participants, including 48 cognitively normal (CN) and 56 SCD, and 96 patients with MCI from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Seed-based locus coeruleus functional connectivity (LC FC) was conducted to detect early brain functional changes in the non-dementia AD spectrum. CR was assessed via years of education and intelligence (IQ). The ANDI composite executive function scores (ADNI-EF) and ADNI composite memory scores (ANDI-MEM) at baseline and 24-month follow-up were used to assess cognitive performance.

RESULTS

Compared to the CN group, the SCD group showed abnormal LC FC with the executive control network (dorsolateral prefrontal cortex, DLPFC), salience network, sensorimotor network, reward network, and hippocampus, while these alterations were inverted at the MCI stage. The LC-hippocampus FC was correlated with ADNI-MEM at baseline and follow-up, and these relationships were moderated by education. The LC-DLPFC FC was correlated with ADNI-EF at baseline, and this association was moderated by IQ.

CONCLUSION

Our results manifested that higher levels of CR would confer protective effects on SCD and MCI. Furthermore, IQ and education could moderate the relationship between LC FC and cognition through different pathways.

The MuSK-BMP pathway regulates synaptic Nav1.4 localization and muscle excitability

The neuromuscular junction (NMJ) is the linchpin of nerve-evoked muscle contraction. Broadly considered, the function of the NMJ is to transduce a nerve action potential into a muscle fiber action potential (MFAP). Efficient information transfer requires both cholinergic signaling, responsible for the generation of endplate potentials (EPPs), and excitation, the activation of postsynaptic voltage-gated sodium channels (Nav1.4) to trigger MFAPs. In contrast to the cholinergic apparatus, the signaling pathways that organize Nav1.4 and muscle fiber excitability are poorly characterized. Muscle-specific kinase (MuSK), in addition to its Ig1 domain-dependent role as an agrin-LRP4 receptor, is also a BMP co-receptor that binds BMPs via its Ig3 domain and shapes BMP-induced signaling and transcriptional output. Here we probed the function of the MuSK-BMP pathway at the NMJ using mice lacking the MuSK Ig3 domain ('ΔIg3-MuSK'). Synapses formed normally in ΔIg3-MuSK animals, but the postsynaptic apparatus was fragmented from the first weeks of life. Anatomical denervation was not observed at any age examined. Moreover, spontaneous and nerve-evoked acetylcholine release, AChR density, and endplate currents were comparable to WT. However, trains of nerve-evoked MFAPs in ΔIg3-MuSK muscle were abnormal as revealed by increased jitter and blocking in single fiber electromyography. Further, nerve-evoked compound muscle action potentials (CMAPs), as well as twitch and tetanic muscle torque force production, were also diminished. Finally, Nav1.4 levels were reduced at ΔIg3-MuSK synapses but not at the extrajunctional sarcolemma, indicating that the observed excitability defects are the result of impaired localization of this voltage-gated ion channel at the NMJ. We propose that MuSK plays two distinct roles at the NMJ: as an agrin-LRP4 receptor necessary for establishing and maintaining cholinergic signaling, and as a BMP co-receptor required for maintaining proper Nav1.4 density, nerve-evoked muscle excitability and force production. The MuSK-BMP pathway thus emerges as a target for modulating excitability and functional innervation, which are defective in conditions such as congenital myasthenic syndromes and aging.

Nrf2 Drives Hepatocellular Carcinoma Progression through Acetyl-CoA-Mediated Metabolic and Epigenetic Regulatory Networks

Correlations between the oxidative stress response and metabolic reprogramming have been observed during malignant tumor formation; however, the detailed mechanism remains elusive. The transcription factor Nrf2, a master regulator of the oxidative stress response, mediates metabolic reprogramming in multiple cancers. In a mouse model of hepatocellular carcinoma (HCC), through metabolic profiling, genome-wide gene expression, and chromatin structure analyses, we present new evidence showing that in addition to altering antioxidative stress response signaling, Nrf2 ablation impairs multiple metabolic pathways to reduce the generation of acetyl-CoA and suppress histone acetylation in tumors, but not in tumor-adjacent normal tissue. Nrf2 ablation and dysregulated histone acetylation impair transcription complex assembly on downstream target antioxidant and metabolic regulatory genes for expression regulation. Mechanistic studies indicate that the regulatory function of Nrf2 is low glucose dependent, the effect of which is demolished under energy refeeding. Together, our results implicate an unexpected effect of Nrf2 on acetyl-CoA generation, in addition to its classic antioxidative stress response regulatory activity, integrates metabolic and epigenetic programs to drive HCC progression.

IMPLICATIONS

This study highlights that Nrf2 integrates metabolic and epigenetic regulatory networks to dictate tumor progression and that Nrf2 targeting is therapeutically exploitable in HCC treatment.

Nrf2 sensitizes ferroptosis through l-2-hydroxyglutarate-mediated chromatin modifications in sickle cell disease

Sickle cell disease (SCD) is a chronic hemolytic and systemic hypoxia condition with constant oxidative stress and significant metabolic alterations. However, little is known about the correlation between metabolic alterations and the pathophysiological symptoms. Here, we report that Nrf2, a master regulator of cellular antioxidant responses, regulates the production of the metabolite l-2-hydroxyglutarate (L2HG) to mediate epigenetic histone hypermethylation for gene expression involved in metabolic, oxidative, and ferroptotic stress responses in SCD. Mechanistically, Nrf2 was found to regulate the expression of L2HG dehydrogenase (L2hgdh) to mediate L2HG production under hypoxia. Gene expression profile analysis indicated that reactive oxygen species (ROS) and ferroptosis responses were the most significantly affected signaling pathways after Nrf2 ablation in SCD. Nrf2 silencing and L2HG supplementation sensitize human sickle erythroid cells to ROS and ferroptosis stress. The absence of Nrf2 and accumulation of L2HG significantly affect histone methylation for chromatin structure modification and reduce the assembly of transcription complexes on downstream target genes to regulate ROS and ferroptosis responses. Furthermore, pharmacological activation of Nrf2 was found to have protective effects against ROS and ferroptosis stress in SCD mice. Our data suggest a novel mechanism by which Nrf2 regulates L2HG levels to mediate SCD severity through ROS and ferroptosis stress responses, suggesting that targeting Nrf2 is a viable therapeutic strategy for ameliorating SCD symptoms.

Study on the emergency capacity of coal mine enterprises in Longdong Area based on D-FAHP method

Emergency capability assessment is a complex system with multiple factors, variables and levels. Incomplete and uncertain assess information often occurs during assessment. Based on this, a method combining D-number theory and fuzzy analytic Hierarchy process (FAHP) is proposed to study the emergency capacity of coal enterprises in Longdong area. On the basis of analyzing the limitation of D-S evidence theory, the D-number theory was optimized and improved. According to the principles of systematicness, feasibility, scientificity and timeliness, a hierarchical structure model of enterprise emergency capability assessment was constructed from the perspective of pre-incident, mid-incident and post-incident, which consisted of 4 first-level indicators and 18 s-level indicators. The weight and importance of the assessment index of emergency response capability are calculated by organically integrating the D-number preference relation with the hierarchy structure. Combined with the assessment results of experts, a quantitative analysis and evaluation of the emergency response capacity of a coal enterprise was conducted by using FAHP. The comprehensive score of the enterprise's emergency response capability was 80.45, and the level of emergency response capacity was "good". The research results show that the D-FAHP method has high reliability in evaluating the emergency response capability of coal enterprises, avoiding the impact of uncertain and incomplete information on the assessment results. This can not only effectively identify the weak links in emergency management, but also meet the emergency decision-making needs of enterprises in the emergency state, which has important guiding significance to improve the ability and level of enterprise emergency management.

Deep learning identified pathological abnormalities predictive of graft loss in kidney transplant biopsies

Interstitial fibrosis, tubular atrophy, and inflammation are major contributors to kidney allograft failure. Here we sought an objective, quantitative pathological assessment of these lesions to improve predictive utility and constructed a deep-learning-based pipeline recognizing normal vs. abnormal kidney tissue compartments and mononuclear leukocyte infiltrates. Periodic acid- Schiff stained slides of transplant biopsies (60 training and 33 testing) were used to quantify pathological lesions specific for interstitium, tubules and mononuclear leukocyte infiltration. The pipeline was applied to the whole slide images from 789 transplant biopsies (478 baseline [pre-implantation] and 311 post-transplant 12-month protocol biopsies) in two independent cohorts (GoCAR: 404 patients, AUSCAD: 212 patients) of transplant recipients to correlate composite lesion features with graft loss. Our model accurately recognized kidney tissue compartments and mononuclear leukocytes. The digital features significantly correlated with revised Banff 2007 scores but were more sensitive to subtle pathological changes below the thresholds in the Banff scores. The Interstitial and Tubular Abnormality Score (ITAS) in baseline samples was highly predictive of one-year graft loss, while a Composite Damage Score in 12-month post-transplant protocol biopsies predicted later graft loss. ITASs and Composite Damage Scores outperformed Banff scores or clinical predictors with superior graft loss prediction accuracy. High/intermediate risk groups stratified by ITASs or Composite Damage Scores also demonstrated significantly higher incidence of estimated glomerular filtration rate decline and subsequent graft damage. Thus, our deep-learning approach accurately detected and quantified pathological lesions from baseline or post-transplant biopsies and demonstrated superior ability for prediction of post-transplant graft loss with potential application as a prevention, risk stratification or monitoring tool.

LncRNA LINC01278 accelerates colorectal cancer progression via miR-134-5p/KDM2A axis

OBJECTIVE

Long non-coding RNAs (lncRNAs) play vital roles in the pathogenesis and development of multiple cancers, including colorectal cancer (CRC). Nevertheless, the regulatory mechanisms of LINC01278 in CRC remain unknown. Our research aims to identify the regulatory mechanisms of LINC01278 in CRC.

PATIENTS AND METHODS

The expression of LINC01278 was examined by quantitative real-time polymerase chain reaction (RT-qPCR). StarBase and TargetScan websites were used to predict the interaction between miR-134 and LINC01278 or KDM2A, which was further confirmed by Dual-Luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell viability, migration, and invasion were detected by Cell Counting Kit-8 (CCK-8) and transwell assays.

RESULTS

LINC01278 was upregulated in CRC tissues and cell lines, and knockdown of LINC01278 suppressed CRC cell progression. In addition, LINC01278 inhibited miR-134 expression by direct interaction, and the inhibition of miR-134 abolished the suppressive effects of LINC01278 knockdown on viability, migration, and invasion of CRC cells. Furthermore, KDM2A was confirmed to be a target gene of miR-134. Overexpression of KDM2A facilitated the tumorigenesis of CRC, while this effect was reversed by the upregulation of miR-143. Finally, it was demonstrated that miR-134 inhibitor reversed the shLINC01278‑mediated inhibitory effect on KDM2A expression.

CONCLUSIONS

Our study demonstrated that LINC01278 upregulated KDM2A to promote CRC progression by interacting with miR-143, suggesting that LINC01278 might be a new therapeutic target of CRC.

Effects of blood pathological changes before TAI on pregnancy of dairy cows with anestrus and estrus

ABSTRACT The objective of this study was to investigate the influence of plasma pathological changes before timed artificial insemination (TAI) on pregnancy of cows. The contents of estrogen (E2), progesterone (P4), glucose (Glu), selenium (Se), brain-derived neurotrophic factor (BDNF), and histamine (HIS) in plasma of 48 Holstein cows were measured before TAI. According to the estrus detection, the cows were divided into estrus (E) and anestrus (A) groups. After pregnancy testing at 28 d after TAI, two groups of E and A were divided into positive pregnancy of E group (EP+), negative pregnancy of E group (EP-), positive pregnancy of A group (AP+), and negative pregnancy of A group (AP-). The contents of E2, P4, Glu, Se, BDNF and hIS significantly differed among the four groups (P<0.01). The ROC analysis was used to determine the risk of negative pregnancy test (-) after TAI was increased when plasma E2 was less than 46.45 pmol/L in cows before TAI. The changes in E2, P4,hIS, Glu, and BDNF in the blood of natural estrus and natural anestrus cows affected the pregnancy after TAI. the level of E2 in plasma may be used to assess the risk of negative pregnancy after TAI.

NRF2 mediates γ-globin gene regulation through epigenetic modifications in a β-YAC transgenic mouse model

IMPACT STATEMENT

Sickle cell disease is an inherited hemoglobin disorder that affects over 100,000 people in the United States causing high morbidity and early mortality. Although new treatments were recently approved by the FDA, only one drug Hydroxyurea induces fetal hemoglobin expression to inhibit sickle hemoglobin polymerization in red blood cells. Our laboratory previously demonstrated the ability of the NRF2 activator, dimethyl fumarate to induce fetal hemoglobin in the sickle cell mouse model. In this study, we investigated molecular mechanisms of γ-globin gene activation by NRF2. We observed the ability of NRF2 to modulate chromatin structure in the human β-like globin gene locus of β-YAC transgenic mice during development. Furthermore, an NRF2/TET3 interaction regulates γ-globin gene DNA methylation. These findings provide potential new molecular targets for small molecule drug developed for treating sickle cell disease.

circ_0007385 served as competing endogenous RNA for miR-519d-3p to suppress malignant behaviors and cisplatin resistance of non-small cell lung cancer cells

Background

Circular RNAs (circRNAs) have been closely implicated in competing endogenous RNA (ceRNA) network among human cancers including non‐small cell lung cancer (NSCLC). However, the role of most circRNAs in NSCLC remains to be determined. Here, we aimed to investigate the role of hsa_circ_0007385 (circ_0007385) in NSCLC cells.

Methods

Expression of hsa_circ_0007385 (circ_0007385), miRNA (miR)‐519d‐5p and high‐mobility group box 1 (HMGB1) was measured by real‐time quantitative PCR and western blotting. Functional experiments were evaluated by cell counting kit (CCK)‐8, flow cytometry, fluorescein active caspase‐3 staining kit, transwell assays, western blotting, and xenograft experiment. The relationship among circ_0007385,miR‐519d‐5p and HMGB1 was testified by dual‐luciferase reporter assay. Kaplan‐Meiersurvival curve identified overall survival in NSCLC patients.

Results

circ_0007385 expression was higher in NSCLC tissues and cell lines, and was associated with poor overall survival. Silencing circ_0007385 could suppress cell proliferation, migration and invasion in A549 and H1975 cells, as well as cisplatin (DDP) resistance. Moreover, circ_0007385 silence retarded tumor growth of A549 cells in vivo. Molecularly, there was a direct interaction between miR‐519d‐3p and either circ_0007385 or HMGB1; expression of miR‐519d‐3p was downregulated in NSCLC tumors in a circ_0007385‐correlated manner, and circ_0007385 could indirectly regulate HMGB1 via miR‐519d‐3p. Functionally, both inhibiting miR‐519d‐3p and restoring HMGB1 could overturn the suppressive effect of circ_0007385 knockdown on cell proliferation, migration, invasion, and DDP resistance.

Conclusions

Collectively, circ_0007385 deletion could function anti‐tumor role in NSCLC by suppressing malignant behaviors and DDP resistance in vitro and in vivo via circ_0007385/miR‐519d‐3p/HMGB1 axis. These outcomes might enhance our understanding of the molecular mechanisms underlying the malignant progression of NSCLC.

Key points

Significant findings of the study

circ_0007385 was upregulated in NSCLC tissues and cells, and was associated with poor overall survival.

Silenced circ_0007385 suppressed NSCLC cell proliferation, migration, invasion, and DDP resistance in vitro, and tumor growth in vivo.

circ_0007385 was upregulated in NSCLC tissues and cells, and was associated with poor overall survival.

What this study adds

miR‐519d‐3p could directly interact with circ_0007385 and HMGB1 in NSCLC cells.

A promising circ_0007385/miR‐519d‐3p/HMGB1 regulatory pathway was determined in NSCLC cells.

HSF1-Mediated Control of Cellular Energy Metabolism and mTORC1 Activation Drive Acute T-Cell Lymphoblastic Leukemia Progression

Deregulated oncogenic signaling linked to PI3K/AKT and mTORC1 pathway activation is a hallmark of human T-cell acute leukemia (T-ALL) pathogenesis and contributes to leukemic cell resistance and adverse prognosis. Notably, although the multiagent chemotherapy of leukemia leads to a high rate of complete remission, options for salvage therapy for relapsed/refractory disease are limited due to the serious side effects of augmenting cytotoxic chemotherapy. We report that ablation of HSF1, a key transcriptional regulator of the chaperone response and cellular bioenergetics, from mouse T-ALL tumors driven by PTEN loss or human T-ALL cell lines, has significant therapeutic effects in reducing tumor burden and sensitizing malignant cell death. From a mechanistic perspective, the enhanced sensitivity of T-ALLs to HSF1 depletion resides in the reduced MAPK-ERK signaling and metabolic and ATP-producing capacity of malignant cells lacking HSF1 activity. Impaired mitochondrial ATP production and decreased intracellular amino acid content in HSF1-deficient T-ALL cells trigger an energy-saving adaptive response featured by attenuation of the mTORC1 activity, which is coregulated by ATP, and its downstream target proteins (p70S6K and 4E-BP). This leads to protein translation attenuation that diminishes oncogenic signals and malignant cell growth. Collectively, these metabolic alterations in the absence of HSF1 activity reveal cancer cell liabilities and have a profound negative impact on T-ALL progression. IMPLICATIONS: Targeting HSF1 and HSF1-dependent cancer-specific anabolic and protein homeostasis programs has a significant therapeutic potential for T-ALL and may prevent progression of relapsed/refractory disease.

A Peripheral Blood Gene Expression Signature to Diagnose Subclinical Acute Rejection

BACKGROUND

In kidney transplant recipients, surveillance biopsies can reveal, despite stable graft function, histologic features of acute rejection and borderline changes that are associated with undesirable graft outcomes. Noninvasive biomarkers of subclinical acute rejection are needed to avoid the risks and costs associated with repeated biopsies.

METHODS

We examined subclinical histologic and functional changes in kidney transplant recipients from the prospective Genomics of Chronic Allograft Rejection (GoCAR) study who underwent surveillance biopsies over 2 years, identifying those with subclinical or borderline acute cellular rejection (ACR) at 3 months (ACR-3) post-transplant. We performed RNA sequencing on whole blood collected from 88 individuals at the time of 3-month surveillance biopsy to identify transcripts associated with ACR-3, developed a novel sequencing-based targeted expression assay, and validated this gene signature in an independent cohort.

RESULTS

Study participants with ACR-3 had significantly higher risk than those without ACR-3 of subsequent clinical acute rejection at 12 and 24 months, faster decline in graft function, and decreased graft survival in adjusted Cox analysis. We identified a 17-gene signature in peripheral blood that accurately diagnosed ACR-3, and validated it using microarray expression profiles of blood samples from 65 transplant recipients in the GoCAR cohort and three public microarray datasets. In an independent cohort of 110 transplant recipients, tests of the targeted expression assay on the basis of the 17-gene set showed that it identified individuals at higher risk of ongoing acute rejection and future graft loss.

CONCLUSIONS

Our targeted expression assay enabled noninvasive diagnosis of subclinical acute rejection and inflammation in the graft and may represent a useful tool to risk-stratify kidney transplant recipients.

Pretransplant transcriptomic signature in peripheral blood predicts early acute rejection

Commonly available clinical parameters fail to predict early acute cellular rejection (EAR, occurring within 6 months after transplant), a major risk factor for graft loss after kidney transplantation. We performed whole-blood RNA sequencing at the time of transplant in 235 kidney transplant recipients enrolled in a prospective cohort study (Genomics of Chronic Allograft Rejection [GoCAR]) and evaluated the relationship of pretransplant transcriptomic profiles with EAR. EAR was associated with downregulation of NK and CD8+ T cell gene signatures in pretransplant blood. We identified a 23-gene set that predicted EAR in the discovery (n = 81, and AUC = 0.80) and validation (n = 74, and AUC = 0.74) sets. Exclusion of recipients with 5 or 6 HLA donor mismatches increased the AUC to 0.89. The risk score derived from the gene set was also significantly associated with acute cellular rejection after 6 months, antibody-mediated rejection and/or de novo donor-specific antibodies, and graft loss in a cohort of 154 patients, combining the validation set and additional GoCAR patients with surveillance biopsies between 6 and 24 months (n = 80) posttransplant. This 23-gene set is a potentially important new tool for determination of the recipient's immunological risk before kidney transplantation, and facilitation of an individualized approach to immunosuppressive therapy.

Alteration of Tumor Metabolism by CD4+ T Cells Leads to TNF-α-Dependent Intensification of Oxidative Stress and Tumor Cell Death

The inhibitory effects of cancer on T cell metabolism have been well established, but the metabolic impact of immunotherapy on tumor cells is poorly understood. Here, we developed a CD4+ T cell-based adoptive immunotherapy protocol that was curative for mice with implanted colorectal tumors. By conducting metabolic profiling on tumors, we show that adoptive immunotherapy profoundly altered tumor metabolism, resulting in glutathione depletion and accumulation of reactive oxygen species (ROS) in tumor cells. We further demonstrate that T cell-derived tumor necrosis factor alpha (TNF-α) can synergize with chemotherapy to intensify oxidative stress and tumor cell death in an NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) oxidase-dependent manner. Reduction of oxidative stress, by preventing TNF-α-signaling in tumor cells or scavenging ROS, antagonized the therapeutic effects of adoptive immunotherapy. Conversely, provision of pro-oxidants after chemotherapy can partially recapitulate the antitumor effects of T cell transfer. These findings imply that reinforcing tumor oxidative stress represents an important mechanism underlying the efficacy of adoptive immunotherapy.

The effect of interactions between a bacterial strain isolated from drinking water and a pathogen surrogate on biofilms formation diverged under static vs flow conditions

AIMS

Interactions with water bacteria affect the incorporation of pathogens into biofilms and thus pathogen control in drinking water systems. This study was to examine the impact of static vs flow conditions on interactions between a pathogen and a water bacterium on pathogen biofilm formation under laboratory settings.

METHODS AND RESULTS

A pathogen surrogate Escherichia coli and a drinking water isolate Stenotrophomonas maltophilia was selected for this study. Biofilm growth was examined under two distinct conditions, in flow cells with continuous medium supply vs in static microtitre plates with batch culture. E. coli biofilm was greatly stimulated (c. 2-1000 times faster) with the presence of S. maltophilia in flow cells, but surprisingly inhibited (c. 65-95% less biomass) in microtitre plates. These divergent effects were explained through various aspects including surface attachment, cellular growth, extracellular signals and autoaggregation.

CONCLUSIONS

Interactions with the same water bacterium resulted in different effects on E. coli biofilm formation when culture conditions changed from static to flow.

SIGNIFICANCE AND IMPACT OF STUDY

This study highlights the complexity of species interactions on biofilm formation and suggests that environmental conditions such as the flow regime can be taken into consideration for the management of microbial contamination in drinking water systems.

Pharmacokinetic and pharmacodynamic integration and modeling of acetylkitasamycin in swine for Clostridium perfringens

The aim of this study was to establish an integrated pharmacokinetic/pharmacodynamic (PK/PD) modeling approach of acetylkitasamycin for designing dosage regimens and decreasing the emergence of drug-resistant bacteria. After oral administration of acetylkitasamycin to healthy and infected pigs at the dose of 50 mg/kg body weights (bw), a rapid and sensitive LC-MS/MS method was developed and validated for determining the concentration change of the major components of acetylkitasamycin and its possible metabolite kitasamycin in the intestinal samples taken from the T-shape ileal cannula. The PK parameters, including the integrated peak concentration (C_max ), the time when the maximum concentration reached (T_max ) and the area under the concentration-time curve (AUC), were calculated by WinNonlin software. The minimum inhibitory concentration (MIC) of 60 C. perfringens strains was determined following CLSI guideline. The in vitro and ex vivo activities of acetylkitasamycin in intestinal tract against a pathogenic strain of C. perfringens type A (CPFK122995) were established by the killing curve. Our PK data showed that the integrated C_max , T_max , and AUC were 14.57-15.81 μg/ml, 0.78-2.52 hR, and 123.84-152.32 μg hr/ml, respectively. The PD data show that MIC₅₀ and MIC₉₀ of the 60 C. perfringens isolates were 3.85 and 26.45 μg/ml, respectively. The ex vivo growth inhibition data were fitted to the inhibitory sigmoid E_max equation to provide the values of AUC/MIC to produce bacteriostasis (4.84 hr), bactericidal activity (15.46 hr), and bacterial eradication (24.99 hr). A dosage regimen of 18.63 mg/kg bw every 12 hr could be sufficient in the prevention of C. perfringens infection. The therapeutic dosage regimen for C. perfringens infection was at the dose of 51.36 mg/kg bw every 12 hr for 3 days. In summary, the dosage regimen for the treatment of C. perfringens in pigs administered with acetylkitasamycin was designed using PK/PD integrate model. The designed dose regimen could to some extent decrease the risk for emergence of macrolide resistance.

Biopsy transcriptome expression profiling to identify kidney transplants at risk of chronic injury: a multicentre, prospective study

BACKGROUND

Chronic injury in kidney transplants remains a major cause of allograft loss. The aim of this study was to identify a gene set capable of predicting renal allografts at risk of progressive injury due to fibrosis.

METHODS

This Genomics of Chronic Allograft Rejection (GoCAR) study is a prospective, multicentre study. We prospectively collected biopsies from renal allograft recipients (n=204) with stable renal function 3 months after transplantation. We used microarray analysis to investigate gene expression in 159 of these tissue samples. We aimed to identify genes that correlated with the Chronic Allograft Damage Index (CADI) score at 12 months, but not fibrosis at the time of the biopsy. We applied a penalised regression model in combination with permutation-based approach to derive an optimal gene set to predict allograft fibrosis. The GoCAR study is registered with ClinicalTrials.gov, number NCT00611702.

FINDINGS

We identified a set of 13 genes that was independently predictive for the development of fibrosis at 1 year (ie, CADI-12 ≥2). The gene set had high predictive capacity (area under the curve [AUC] 0·967), which was superior to that of baseline clinical variables (AUC 0·706) and clinical and pathological variables (AUC 0·806). Furthermore routine pathological variables were unable to identify which histologically normal allografts would progress to fibrosis (AUC 0·754), whereas the predictive gene set accurately discriminated between transplants at high and low risk of progression (AUC 0·916). The 13 genes also accurately predicted early allograft loss (AUC 0·842 at 2 years and 0·844 at 3 years). We validated the predictive value of this gene set in an independent cohort from the GoCAR study (n=45, AUC 0·866) and two independent, publically available expression datasets (n=282, AUC 0·831 and n=24, AUC 0·972).

INTERPRETATION

Our results suggest that this set of 13 genes could be used to identify kidney transplant recipients at risk of allograft loss before the development of irreversible damage, thus allowing therapy to be modified to prevent progression to fibrosis.

FUNDING

National Institutes of Health.

Evaluation of the ability of Acinetobacter baumannii to form biofilms on six different biomedical relevant surfaces

The human opportunistic pathogen, Acinetobacter baumannii, has the propensity to form biofilms and frequently cause medical device-related infections in hospitals. However, the physio-chemical properties of medical surfaces, in addition to bacterial surface properties, will affect colonization and biofilm development. The objective of this study was to compare the ability of A. baumannii to form biofilms on six different materials common to the hospital environment: glass, porcelain, stainless steel, rubber, polycarbonate plastic and polypropylene plastic. Biofilms were developed on material coupons in a CDC biofilm reactor. Biofilms were visualized and quantified using fluorescent staining and imaged using confocal laser scanning microscopy (CLSM) and by direct viable cell counts. Image analysis of CLSM stacks indicated that the mean biomass values for biofilms grown on glass, rubber, porcelain, polypropylene, stainless steel and polycarbonate were 0·04, 0·26, 0·62, 1·00, 2·08 and 2·70 μm(3) /μm(2) respectively. Polycarbonate developed statistically more biofilm mass than glass, rubber, porcelain and polypropylene. Viable cell counts data were in agreement with the CLSM-derived data. In conclusion, polycarbonate was the most accommodating surface for A. baumannii ATCC 17978 to form biofilms while glass was least favourable. Alternatives to polycarbonate for use in medical and dental devices may need to be considered.

SIGNIFICANCE AND IMPACT OF THE STUDY

In the hospital environment, Acinetobacter baumannii is one of the most persistent and difficult to control opportunistic pathogens. The persistence of A. baumannii is due, in part, to its ability to colonize surfaces and form biofilms. This study demonstrates that A. baumannii can form biofilms on a variety of different surfaces and develops substantial biofilms on polycarbonate - a thermoplastic material that is often used in the construction of medical devices. The findings highlight the need to further study the in vitro compatibility of medical materials that could be colonized by A. baumannii and allow it to persist in hospital settings.

Mini-review: Microbial coaggregation: ubiquity and implications for biofilm development

Coaggregation is the specific recognition and adherence of genetically distinct microorganisms. Because most biofilms are polymicrobial communities, there is potential for coaggregation to play an integral role in spatiotemporal biofilm development and the moderation of biofilm community composition. However, understanding of the mechanisms contributing to coaggregation and the relevance of coaggregation to biofilm ecology is at a very early stage. The purpose of this review is to highlight recent advances in the understanding of microbial coaggregation within different environments and to describe the possible ecological ramifications of such interactions. Bacteria that coaggregate with many partner species within different environments will be highlighted, including oral streptococci and oral bridging organisms such as fusobacteria, as well as the freshwater sphingomonads and acinetobacters. Irrespective of environment, it is proposed that coaggregation is essential for the orchestrated development of multi-species biofilms.

Heat shock factor Hsf1 cooperates with ErbB2 (Her2/Neu) protein to promote mammary tumorigenesis and metastasis

ErbB2/Neu oncogene is overexpressed in 25% of invasive/metastatic breast cancers. We have found that deletion of heat shock factor Hsf1 in mice overexpressing ErbB2/Neu significantly reduces mammary tumorigenesis and metastasis. Hsf1(+/-)ErbB2/Neu(+) tumors exhibit reduced cellular proliferative and invasive properties associated with reduced activated ERK1/2 and reduced epithelial-mesenchymal transition (EMT). Hsf1(+/+)Neu(+) mammary epithelial cells exposed to TGFβ show high levels of ERK1/2 activity and EMT; this is associated with reduced expression of E-cadherin and increased expression of Slug and vimentin, a mesenchymal marker. In contrast, Hsf1(-/-)Neu(+) or Hsf1(+/+)Neu(+) cells do not exhibit activated ERK1/2 and show reduced EMT in the presence of TGFβ. The ineffective activation of the RAS/RAF/MEK/ERK1/2 signaling pathway in cells with reduced levels of HSF1 is due to the low levels of HSP90 in complex with RAF1 that are required for RAF1 stability and maturation. These results indicate a powerful inhibitory effect conferred by HSF1 downstream target genes in the inhibition of ErbB2-induced breast cancers in the absence of the Hsf1 gene.

A novel recombinant peptide containing only two T-cell tolerance epitopes of chicken type II collagen that suppresses collagen-induced arthritis

Immunotherapy of rheumatoid arthritis (RA) using oral-dosed native chicken or bovine type II collagen (nCII) to induce specific immune tolerance is an attractive strategy. However, the majority of clinical trials of oral tolerance in human diseases including RA in recent years have been disappointing. Here, we describe a novel recombinant peptide rcCTE1-2 which contains only two tolerogenic epitopes (CTE1 and CTE2) of chicken type II collagen (cCII). These are the critical T-cell determinants for suppression of RA that were first developed and used to compare its suppressive effects with ncCII on the collagen-induced arthritis (CIA) model. The rcCTE1-2 was produced using the prokaryotic pET expression system and purified by Ni-NTA His affinity chromatography. Strikingly, our results showed clearly that rcCTE1-2 was as efficacious as ncCII at the dose of 50 microg/kg/d. This dose significantly reduced footpad swelling, arthritic incidence and scores, and deferred the onset of disease. Furthermore, rcCTE1-2 of 50 microg/kg/d could lower the level of anti-nCII antibody in the serum of CIA animals, decrease Th1-cytokine INF-gamma level, and increase Th3-cytokine TGF-beta(1) produced level by spleen cells from CIA mice after in vivo stimulation with ncCII. Importantly, rcCTE1-2 was even more potent than native cCII, which was used in the clinic for RA. Equally importantly, the findings that the major T-cell determinants of cCII that are also recognized by H-2(b) MHC-restricted T cells have not previously been reported. Taken together, these results suggest that we have successfully developed a novel recombinant peptide rcCTE1-2 that can induce a potent tolerogenic response in CIA.

Molecular construction and characterization of a novel exotoxin fusion protein that selectively blocks the B7:CD28 costimulatory signal system

An important strategy for specifically preventing and treating graft-versus-host and host-versus-graft diseases is to selectively block the B7:CD28/cytotoxic T-lymphocyte A4 costimulatory signal system for induced immune tolerance. In this study, a novel recombinant B7-2-L-PE40KDEL fusion protein was created to target the B7:CD28 system. We used a flexible linker sequence (Gly4Ser)4 and overlapping sequence extension to link the cDNAs encoding a human B7-2 extracellular domain and a mutant truncated form of Pseudomonas exotoxin A (PE), PE40KDEL. This B7-2-L-PE40KDEL fusion gene was then inserted into the pTYB4 expression vector, expressed in Escherichia coli, and purified through Ni-NTA mealty affinity-->MonoQ anion exchange-->Superdex75 gel filtration chromatography 3-step purification protocols. Western blotting demonstrated that the B7-2-L-PE40KDEL fusion protein specifically bound antihuman B7-2 monoclonal antibody and anti-pseudomonas exotoxin A antiserum. We used the Antheprot nucleic acid and protein analyzing software to predict the characteristics of this fusion protein, and showed that the fusion did not confer new antigenicities to the fusion protein. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests demonstrated that at doses ranging from 0.2 to 2 microg/mL, this fusion protein specifically killed CD28-overexpressing Jurkat cells but even at doses of 2 microg did not kill CD28-negative Hut28 cells. The results of a one-way mixed lymphocyte reaction demonstrated that the fusion protein has a range of suppressive effects on HLA class I and II matched related donors and recipients, and HLA class I and II mismatched unrelated donors. Taken together, these results demonstrate that we have developed a novel recombinant human B7-2-L-PE40KDEL exotoxin fusion protein that specifically blocks the B7:CD28 costimulatory signal system in a manner that may be of significant importance in preventing and treating graft-versus-host or host-versus-graft diseases.

Molecular cloning, characterization and localization of chicken type II procollagen gene

Chicken type II procollagen (ccol2a1) has become as an important oral tolerance protein for effective treatment of rheumatoid arthritis. However, its molecular identity remains unclear. Here, we reported the full-length cDNA and nearly complete genomic DNA encoding ccol2a1. We have determined the structural organization, evolutional characters, developmental expression and chromosomal mapping of the gene. The full-length cDNA sequence spans 4837 bp containing all the coding region of the ccol2a1 including 3' and 5' untranslation region. The deduced peptide of ccol2a1, composed of 1420 amino acids, can be divided into signal peptide, N-propeptide, N-telopeptide, triple helix, C-telopeptide and C-propeptide. The ccol2a1 genomic DNA sequence was determined to be 12,523 bp long containing 54 exons interrupted by 53 introns. Comparison of the ccol2a1 with its counterparts in human, mouse, canine, horse, rat, frog and newt revealed highly conserved sequence in the triple helix domain. Chromosomal mapping of ccol2a1 locates it on 4P2. While the ccol2a1 mRNA was expressed in multiple tissues, the protein was only detected in chondrogenic cartilage, vitreous body and cornea. The ccol2a1 was found to contain two isoforms detected by RT-PCR. The distribution of the ccol2a1 lacking exon 2wasfrequently detected in chondrogenic tissues, whereas the exon 2-containing isoform was more abundant in non-chondrogenic tissues. These results provide useful information for preparing recombinant chicken type II collagen and for a better understanding of normal cartilage development.

Processing and export of peptide pheromones and bacteriocins in Gram-negative bacteria

Cell-density-dependent gene expression is widespread in bacteria and is mediated by extracellular communication molecules. Gram-negative bacteria often use N-acyl homoserine lactones, whereas cell-cell signaling in Gram-positive bacteria is accomplished using post-translationally processed peptide pheromones. In many Gram-positive bacteria, export of these peptides requires the activity of a dedicated ATP-binding cassette (ABC) transporter, which cleaves off a typical leader peptide termed the double-glycine leader sequence concomitant with translocation across the membrane. Inspection of bacterial genome sequences has revealed the presence of similar ABC transporters, as well as genes encoding peptides with double-glycine-type leader sequences in Gram-negative bacteria, and it is suggested that the postulated transported peptides could perform a signaling function.

Use of Dual Marker Transposons to Identify New Symbiosis Genes in Rhizobium

Rhizobium etli elicits nitrogen-fixing nodules on the roots of Phaseolus vulgaris. Using a composite dual-marker mini-Tn5 transposon carrying combinations of a constitutively expressed gfp gene and a promoterless gusA gene, we identified novel genes required for an efficient symbiosis. The induction of the gusA gene was used to determine the expression level of the different target genes under conditions partly mimicking the symbiotic environment ex planta. The green fluorescence was used to localize the bacteria in infection threads or inside the plant cells. Among the identified R. etli mutants, several produced a Nod- phenotype, whereas others were Fix- or displayed a reduced acetylene reduction activity during symbiosis. Partial sequence analysis of the mutated genes allowed us to classify them as nodulation genes, nitrogen fixation genes, genes possessing various enzymatic functions previously not yet associated with symbiosis, and genes displaying no similarity to any other sequence in the database. This methodology can be used to screen large numbers of mutants in the search for novel genes important for Rhizobium-legume symbiosis, and may be adapted to study other plant-bacterium interactions.

[Environmental impact of oil pollutant on groundwater during oilfield exploitation in Daqing--a modelling analysis]

This paper analyzed the pollution sources and paths of groundwater environment in Longnan of Daqing during oilfield exploitation. Based on the technological characteristics of oilfield exploitation, a mathematical model on the migration and transformation of oil pollutants was developed, in which, the degradability and the adsorption capacity of oil pollutants were taken into account. An analytical formula of oil pollutant migration in groundwater was derived with continuous sources, and a prediction on the migration was made, which provide an important basis for the environmental impact assessment of oilfield exploitation project.

The enhanced electrogenerated chemiluminescence of Ru(bpy)3(2+) by glutathione on a glassy carbon electrode modified with some porphine compounds

It has been found that the electrochemical activity of glutathione was increased greatly at the glassy carbon electrodes modified with 5,10,15,20-tetraphenylporphine ruthenium(II) carbenyl (RuTPP), meso-tetraphenylporphine copper(II) complex (CuTTP) and hemin. It has been also found that glutathione would enhance the electrogenerated chemiluminescence (ECL) of Ru(bpy)3(2+) at a hemin glassy carbon electrode; the enhanced ECL intensity was linear with the concentration of glutathione in the range of 1 x 10(-7)-1 x 10(-4) mol l-1, based on which method for determination of glutathione has been developed. The detection limit of glutathione was 2 x 10(-8) mol l-1, and the relative standard deviation for 1 x 10(-6) mol l-1 glutathione was 2.7%. The mechanism for this ECL system has been proposed.

Symbiosis-specific expression of Rhizobium etli casA encoding a secreted calmodulin-related protein

Symbiosis between Rhizobium and its leguminous host requires elaborate communication between the partners throughout the interaction process. A calmodulin-like protein, termed calsymin, was identified in Rhizobium etli; a calmodulin-related protein in a Gram-negative bacterium had not been described previously. Calsymin possesses three repeated homologous domains. Each domain contains two predicted EF-hand Ca(2+)-binding motifs. Ca(2+)-binding activity of calsymin was demonstrated on purified protein. R. etli efficiently secretes calsymin without N-terminal cleavage of the protein. The gene encoding calsymin, casA, is exclusively expressed during colonization and infection of R. etli with the host. Expression of casA is controlled by a repressor protein, termed CasR, belonging to the TetR family of regulatory proteins. Mutation of the casA gene affects the development of bacteroids during symbiosis and symbiotic nitrogen fixation.

Bi-functional gfp- and gusA-containing mini-Tn5 transposon derivatives for combined gene expression and bacterial localization studies

The gfp gene, encoding the green fluorescent protein, was combined with the gusA gene, coding for the beta-glucuronidase enzyme, in mini-Tn5 transposon derivatives for use in Gram-negative bacteria. These mini-Tn5 elements allow simultaneously monitoring of gene expression and localization of the marked bacteria. Introduction of the resultant mini-Tn5 transposons into Rhizobium etli, Azospirillum brasilense and Pseudomonas stutzeri allowed us to visualise the interaction of these bacteria with their host plant. The dual-marker mini-Tn5 transposons constitute a powerful new tool for studying gene expression and ecology of bacteria in the environment and during the interaction with plants.

[The prospective study of the influence of cytomegalovirus (CMV) infection of pregnant women to fetus]

Screening of CMV infection in 450 pregnant women in Shenyang was carried on by ELISA and PCR methods, and CMV infection was detected in 100 of their infants prospectively. The results were 97.11% of pregnant women with past infection, 0.89% with primary infection, 11.11% with recurrent infection, only 2% were susceptible. From 450 pregnant women, there were 3 infants with congenital defects and 3 abortions in active infective group, who were positive for IgM antibody, CMV DNA were positive in heparin peripheral blood, cervical secretion, placenta or amnionic fluid. The fetal infection rate and congenital defect rate in infective group were higher than that in inactive control group. Within 100 maternal-infant pair group, congenitally infected infants were 1.43 times higher in infective group than that in control group (RR = 1.43). Two infants with mental retardations (MDI<70) were born in infective group, but none in control group. In our study, primary infection of early pregnancy was most harmful to fetus, the intrauterine transmission rate was 33.3%. Among nine infected infants born from the infective group, two infants were with CID, and seven were symptomless. CMV screening is important for pregnant women in view of eugenic. When active CMV infection is found in early pregnancy, termination of pregnancy is better considered while CMV detection of amniotic fluid is also positive.