Epigenetic programming mediates abnormal gut microbiota and disease susceptibility in offspring with prenatal dexamethasone exposure

Prenatal dexamethasone exposure (PDE) can lead to increased susceptibility to various diseases in adult offspring, but its effect on gut microbiota composition and the relationship with disease susceptibility remains unclear. In this study, we find sex-differential changes in the gut microbiota of 6-month-old infants with prenatal dexamethasone therapy (PDT) that persisted in female infants up to 2.5 years of age with altered bile acid metabolism. PDE female offspring rats show abnormal colonization and composition of gut microbiota and increased susceptibility to cholestatic liver injury. The aberrant gut microbiota colonization in the PDE offspring can be attributed to the inhibited Muc2 expression caused by decreased CDX2 expression before and after birth. Integrating animal and cell experiments, we further confirm that dexamethasone could inhibit Muc2 expression by activating GR/HDAC11 signaling and regulating CDX2 epigenetic modification. This study interprets abnormal gut microbiota and disease susceptibility in PDT offspring from intrauterine intestinal dysplasia.

Compositional and functional aberrance of the gut microbiota in treatment-naïve patients with primary Sjögren's syndrome

OBJECTIVES

To investigate the compositional and functional characteristics of the gut microbiota in primary Sjögren's syndrome (pSS) and compare them with those in systemic lupus erythematosus (SLE).

METHODS

Stool samples from 78 treatment-naïve pSS patients and 78 matched healthy controls were detected by shotgun metagenomic sequencing and compared with those from 49 treatment-naïve SLE patients. The virulence loads and mimotopes of the gut microbiota were also assessed by sequence alignment.

RESULTS

The gut microbiota of treatment-naïve pSS patients had lower richness and evenness and showed a different community distribution than that of healthy controls. The microbial species enriched in the pSS-associated gut microbiota included Lactobacillus salivarius, Bacteroides fragilis, Ruminococcus gnavus, Clostridium bartlettii, Clostridium bolteae, Veillonella parvula, and Streptococcus parasanguinis. Lactobacillus salivarius was the most discriminating species in the pSS patients, especially in those with interstitial lung disease (ILD). Among the differentiating microbial pathways, the superpathway of l-phenylalanine biosynthesis was also further enriched in pSS complicated with ILD. There were more virulence genes carried by the gut microbiota in pSS patients, most of which encoded peritrichous flagella, fimbriae, or curli fimbriae, three types of bacterial surface organelles involved in bacterial colonization and invasion. Five microbial peptides with the potential to mimic pSS-related autoepitopes were also enriched in the pSS gut. SLE and pSS shared significant gut microbial traits, including community distribution, altered microbial taxonomy and pathways, and enriched virulence genes. However, Ruminococcus torques was depleted in pSS patients but enriched in SLE patients compared to healthy controls.

CONCLUSIONS

The gut microbiota in treatment-naïve pSS patients was disturbed and shared significant similarity with that in SLE patients.

Microbiota-indole 3-propionic acid-brain axis mediates abnormal synaptic pruning of hippocampal microglia and susceptibility to ASD in IUGR offspring

BACKGROUND

Autism spectrum disorder (ASD) has been associated with intrauterine growth restriction (IUGR), but the underlying mechanisms are unclear.

RESULTS

We found that the IUGR rat model induced by prenatal caffeine exposure (PCE) showed ASD-like symptoms, accompanied by altered gut microbiota and reduced production of indole 3-propionic acid (IPA), a microbiota-specific metabolite and a ligand of aryl hydrocarbon receptor (AHR). IUGR children also had a reduced serum IPA level consistent with the animal model. We demonstrated that the dysregulated IPA/AHR/NF-κB signaling caused by disturbed gut microbiota mediated the hippocampal microglia hyperactivation and neuronal synapse over-pruning in the PCE-induced IUGR rats. Moreover, postnatal IPA supplementation restored the ASD-like symptoms and the underlying hippocampal lesions in the IUGR rats.

CONCLUSIONS

This study suggests that the microbiota-IPA-brain axis regulates ASD susceptibility in PCE-induced IUGR offspring, and supplementation of microbiota-derived IPA might be a promising interventional strategy for ASD with a fetal origin. Video Abstract.

Disturbed gut virome with potent interferonogenic property in systemic lupus erythematosus

Accumulating evidence suggests an essential role of disturbed gut microbiota in the etiopathogenesis of systemic lupus erythematosus (SLE), but it remains unclear as to gut virome. In this study, fecal virus-like particles (VLPs) isolated from 76 non-treated SLE patients and 75 healthy controls were subjected to gut virome profiling. The proportion of bacteriophages was significantly elevated in the SLE gut, and the altered viral taxa were correlated with clinical parameters. Gut virome and bacteriome were closely associated with each other in SLE patients. The combination of gut viral and bacterial markers displayed better performance in distinguishing SLE patients from healthy controls. Further, VLPs from non-treated SLE patients promoted interferon-α production in an epithelial cell line and human immune cells. Intriguingly, the interferon-stimulatory capacity diminished in VLPs from post-treated SLE patients. Our findings may shed novel insights into SLE pathogenesis. Further in-depth understanding of gut virome might help develop future biomarkers and therapeutics for SLE patients.

Impact of targeted therapies on the risk of cardiovascular events in patients with psoriasis and psoriatic arthritis: A systematic review and aggregate data meta-analysis of randomized controlled trials

OBJECTIVE

We aimed to investigate the effect of targeted therapies on cardiovascular risk in psoriasis (PsO) and psoriatic arthritis (PsA) via a meta-analysis of randomized controlled trials (RCTs).

METHODS

Pubmed, Embase, Cochrane Library, and Scopus were searched for RCTs reporting targeted therapies in patients with PsO/PsA published until 28 October 2021. The primary and secondary outcomes included the relationship between targeted therapies and all cardiovascular events (CVEs), major adverse cardiovascular events (MACEs), myocardial infarction (MI), heart failure, and stroke in PsO/PsA. The outcome risk ratios (RRs) were calculated using the Mantel-Haenszel fixed-effect method.

RESULTS

A total of 81 articles involving 88 RCTs were included. There was no statistically significant difference regarding the occurrence of all CVEs for all targeted therapies (RR = 1.03, 95% CI 0.74-1.43, P = .85) compared to placebo in PsO/PsA. No statistically significant difference existed between drugs and placebo in patients with PsA on all CVEs (RR = 0.81, 95% CI 0.48-1.36, P = .43). Surprisingly, the incidence of all CVEs was higher in the low dosage group compared to the high dosage group of all targeted therapies (RR = 1.97, 95% CI 1.19-3.27, P = .008) and prominently anti-interleukin-17 agent (RR = 2.20, 95% CI 1.05-4.58, P = .04).

CONCLUSION

Current targeted therapies are not associated with the risk of CVEs. Based on the existing evidence, we reported here that a dosage reduction of targeted therapies was not recommended.

Numerical Simulation on Laser Shock Peening of B4C-TiB2 Composite Ceramics

The introduction of residual stresses using laser shock peening (LSP) is an effective means of improving the mechanical properties of ceramics. Numerical simulations offer greater convenience and efficiency than in-lab experiments when testing the effects of different processing techniques on residual stress distribution. In this work, a B₄C-TiB₂ ceramic model based on the extended Drucker-Prager model was established to investigate the effects of laser power density, the number of impacts and laser spot overlapping rate on the residual stress distribution, and the reliability of the simulation method was verified by experimental data. The following results are obtained: increasing the laser power density and the number of impacts can increase the surface residual compressive stress and reduce the depth of the residual compressive stress; the presence of multiple impacts will significantly reduce the depth of the residual compressive stress layer; with the increase in the laser spot overlapping rate, the compressive residual stress in the processed area gradually increases and is more uniformly distributed; the best processing effect can be achieved by using a spot overlapping rate of 50%.

Development of a Diagnostic Model Focusing on Esophageal Dysmotility in Patients with Systemic Sclerosis

OBJECTIVE

Esophageal dysmotility is a common and neglected complication of systemic sclerosis (SSc) associated with poor prognosis, while the assessment remains a challenge. We aimed to develop a diagnostic model for esophageal dysmotility in SSc patients that provides individualized risk estimates.

METHODS

Seventy-five SSc patients who underwent high-resolution manometry (HRM) were included in the study. Esophageal widest diameter (WED) was measured on a chest CT scan. Esophageal parameters between patients with and without esophageal dysmotility were compared. Multivariate logistic regression analysis and Least Absolute Shrinkage and Selection Operator (LASSO) regression were used to fit the model. The diagnostic model was evaluated by discrimination and calibration. Internal validation was estimated using the enhanced bootstrap method with 1000 repetitions.

RESULTS

Sixty-one systemic sclerosis patients (81.3%) were diagnosed with esophageal dysmotility according to the Chicago Classification v 3.0. The diagnostic model for evaluating the probability of esophageal dysmotility integrated clinical and imaging features, including disease duration, ILD, and WED. The model displayed good discrimination with an area under the curve (AUC) of 0.923 (95% CI: 0.837-1.000), a Brier score of 0.083, and good calibration. A high AUC value of 0.911 could still be achieved in the internal validation.

CONCLUSION

The diagnostic model, which combines the disease duration, ILD, and imaging feature (WED), is an effective and noninvasive method for predicting esophageal dysmotility in SSc patients.

Compositional and functional aberrance of the gut microbiota in treatment naïve patients with primary Sjögren's syndrome

OBJECTIVES

To investigate the compositional and functional characteristics of the gut microbiota in primary Sjögren's syndrome (pSS) and compare them with those in systemic lupus erythematosus (SLE).

METHODS

Stool samples from 78 treatment naïve pSS patients and 78 matched healthy controls were detected by shotgun metagenomic sequencing and compared with those from 49 treatment naïve SLE patients. The virulence loads and mimotopes of the gut microbiota were also assessed by sequence alignment.

RESULTS

The gut microbiota of treatment naïve pSS patients had lower richness and evenness and showed a different community distribution than that of healthy controls. The microbial species enriched in the pSS-associated gut microbiota included Lactobacillus salivarius, Bacteroides fragilis, Ruminococcus gnavus, Clostridium bartlettii, Clostridium bolteae, Veillonella parvula, and Streptococcus parasanguinis. Lactobacillus salivarius was the most discriminating species in the pSS patients, especially in those with interstitial lung disease (ILD). Among the differentiating microbial pathways, the superpathway of l-phenylalanine biosynthesis was also further enriched in pSS complicated with ILD. There were more virulence genes carried by the gut microbiota in pSS patients, most of which encoded peritrichous flagella, fimbriae, or curli fimbriae, three types of bacterial surface organelles involved in bacterial colonization and invasion. Five microbial peptides with the potential to mimic pSS-related autoepitopes were also enriched in the pSS gut. SLE and pSS shared significant gut microbial traits, including the community distribution, altered microbial taxonomy and pathways, and enriched virulence genes. However, Ruminococcus torques was depleted in pSS patients but enriched in SLE patients compared to that in healthy controls.

CONCLUSIONS

The gut microbiota in treatment naïve pSS patients was disturbed and shared significant similarity with that in SLE patients.

[Fecal Microbiota Transplantation:Traditional Chinese Medicine Meets Western Medicine]

Fecal microbiota transplantation (FMT) is a therapy of transplanting the functional flora from the feces of a healthy donor into the gastrointestinal tract of a patient to reconstruct the normal flora.The application of FMT in western medicine dates from the 1950s.After decades of development,the efficacy of FMT has been proven in a variety of diseases.The record of FMT in traditional Chinese medicine (TCM) dates early from the 3rd century A.D.,and relevant theories have been recorded in many TCM works in the past dynasties.FMT as a therapy that has been written into guidelines has been accepted by some countries and regions such as the United States and the United Kingdom in the treatment of Clostridium difficile infection,and its clinical indications are expanding.TCM and western medicine,with different medical thoughts,meet in the application of FMT.Exploring a normative and effective FMT procedure reflects not only the patient-centered principle but also the mutual promotion of TCM and western medicine.

Mild cognitive impairment in patients with systemic sclerosis and features analysis

Objective

Nervous system damage in patients with SSc has recently attracted attention. In this study, we aimed to explore mild cognitive impairment (MCI) in SSc patients and the characteristics of these patients.

Methods

A total of 103 SSc patients were consecutively enrolled from July 2018 to May 2019, and 97 matched healthy individuals were also included as controls. Brief cognitive tests, such as the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ), were used to assess the cognitive function of all subjects. We compared the differences in MCI between SSc patients and healthy controls, as well as the differences in demographic and clinical features between SSc patients with and without MCI. Associations of quantitative demographic and clinical features with MoCA-BJ scores in the SSc patients were also evaluated.

Results

The score of MoCA-BJ was lower in the SSc group compared with those in the healthy group [24 (9–30) vs 26 (15–30), P < 0.001]. MCI (MoCA-BJ score ≤ 25) was found in 61.2% (63/103) of the enrolled SSc patients but only in 27.8% (27/97) of the healthy individuals. Other tests evaluating some of the specific domains of cognitive functions showed that the SSc patients had impaired memory, attention and executive ability. Compared with SSc patients without MCI, SSc patients with MCI had lower education level, total serum protein and serum albumin but higher ANA positivity.

Conclusion

MCI is common in patients with SSc and should be drawn to the attention of rheumatologists. Lower education level, malnutrition and higher ANA positivity were closely related to the cognitive dysfunctions in SSc patients, providing directions for further interventions.

Gut Microbiota in Lupus: a Butterfly Effect?

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease that typically displays chronic inflammatory tissue damage and miscellaneous circulatory autoantibodies, as well as distinctive type 1 interferon signatures. The etiology of SLE is unclear and currently is attributed to genetic predisposition and environmental triggers. Gut microbiota has recently been considered a critical environmental pathogenic factor in immune-related disorders, and studies are ongoing to uncover the key pathogens and the imputative mechanisms. Fundamental advancements on the role of the microbiota in SLE pathology have been achieved in recent years and are summarized in this review.

RECENT FINDINGS

Recent findings suggested that gut commensals could propagate autoimmunity via molecular mimicry in which ortholog-carrying microbes cross-activate autoreactive T/B cells and trigger the response against host autoantigens, or via bystander activation by stimulating antigen-presenting cells that present autoantigens and enhancing the expression of co-stimulatory molecules and cytokines, thus leading to the loss of self-tolerance and the production of autoantibodies. Additionally, the break of gut barrier and the translocation of gut commensals to inner organs can trigger immune dysregulation and inappropriate systemic inflammation. All these microbiota-mediated mechanisms could contribute to lupus immunopathogenesis and promote disease development in susceptible individuals. Evidence of the causative role of disturbed gut microbiome in SLE is still limited, and the related molecular mechanisms and pathways are largely elusive. However, the modification of gut microbiota, such as pathobiont vaccine, special diet, restricted consortium transplantation, as well as regulatory metabolites supplementation, might be promising strategies for lupus prophylaxis and treatment.

An Autoimmunogenic and Proinflammatory Profile Defined by the Gut Microbiota of Patients With Untreated Systemic Lupus Erythematosus

OBJECTIVE

Changes in gut microbiota have been linked to systemic lupus erythematosus (SLE), but knowledge is limited. Our study aimed to provide an in-depth understanding of the contribution of gut microbiota to the immunopathogenesis of SLE.

METHODS

Fecal metagenomes from 117 patients with untreated SLE and 52 SLE patients posttreatment were aligned with 115 matched healthy controls and analyzed by whole-genome profiling. For comparison, we assessed the fecal metagenome of MRL/lpr mice. The oral microbiota origin of the gut species that existed in SLE patients was documented by single-nucleotide polymorphism-based strain-level analyses. Functional validation assays were performed to demonstrate the molecular mimicry of newly found microbial peptides.

RESULTS

Gut microbiota from individuals with SLE displayed significant differences in microbial composition and function compared to healthy controls. Certain species, including the Clostridium species ATCC BAA-442 as well as Atopobium rimae, Shuttleworthia satelles, Actinomyces massiliensis, Bacteroides fragilis, and Clostridium leptum, were enriched in SLE gut microbiota and reduced after treatment. Enhanced lipopolysaccharide biosynthesis aligned with reduced branched chain amino acid biosynthesis was observed in the gut of SLE patients. The findings in mice were consistent with our findings in human subjects. Interestingly, some species with an oral microbiota origin were enriched in the gut of SLE patients. Functional validation assays demonstrated the proinflammatory capacities of some microbial peptides derived from SLE-enriched species.

CONCLUSION

This study provides detailed information on the microbiota of untreated patients with SLE, including their functional signatures, similarities with murine counterparts, oral origin, and the definition of autoantigen-mimicking peptides. Our data demonstrate that microbiome-altering approaches may offer valuable adjuvant therapies in SLE.

The Gut Microbiota: Emerging Evidence in Autoimmune Diseases

The pathogenesis of autoimmune diseases (AIDs) is not only attributed to genetic susceptibilities but also environmental factors, among which, disturbed gut microbiota has attracted increasing attention. Compositional and functional changes of gut microbiota have been reported in various AIDs, and increasing evidence suggests that disturbed gut microbiota contributes to their immunopathogenesis. The accepted mechanisms include abnormal microbial translocation, molecular mimicry, and dysregulation of both local and systemic immunity. Studies have also suggested microbiota-based classification models and therapeutic interventions for patients with AIDs. Further in-depth mechanistic studies on microbiota-autoimmunity interplay in AIDs are urgently needed and underway to explore novel and precise diagnostic biomarkers and develop disease and patient-tailored therapeutic strategies.

[The role of facial nerve motor evoked potentials in predicting facial nerve function in vestibular schwannoma surgery]

Objective: To analyze the role of facial nerve motor evoked potentials in predicting facial nerve function in vestibular schwannoma surgery. Methods: In a retrospective clinical study of 226 patients with acoustic neuroma, admitted to our hospital from January 2016 to May 2019, were investigated by facial nerve motor evoked potentials (FNMEP) elicited by multi-pulse transcranial electrical motor cortex stimulation from. For recording the same electrode set-up was used as for continuous EMG monitoring of the orbicularis oculi,oris muscles and mentalis. Pre-surgical (opening dural), intraoperative and post-surgical (closing dural) FNMEP amplitudes and latencies were recorded. End (closing dura) to start (opening dura) amplitude ratios were compared to early-term(3 day after surgery) facial nerve function by House-Brackmann(HB) Grading. Results: 201 patients(88.9%) get a total tumor resection, 15 patients (6.6%) were a subtotal resection, 10 patients(4.4%) were a partial resection. 100 percent of patients had a integrated anatomical preservation of facial nerves, there were four (1.8%) death cases in this group. Reliable FNMEPs were obtained in all patients. The ratio of end-operative to start-operative FNMEP-amplitude showed a negative correlation with early facial nerve function. Correlation was especially close with early function: an amplitude preservation rate of 85.3% led to HB Ⅰ or Ⅱ in 190(84.1%) patients, of 45.6% to HB Ⅲ in 17(7.5%) patients, of 23.1% to HB Ⅳ in 13(5.8%) patients and of 6.7% to HB Ⅴor Ⅵ in 6(2.7%) patients. There was a negative correlation between FNMEP amplitude ratio and post-surgical early HB grading(r=-0.895, P=0.000). Conclusion: FNMEP was highly reliable in predicting early postoperative facial function of the resection of vestibular schwannoma, was a valid protection technique of facial nerve.

[Research progress of alpha-fetoprotein vaccine in hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) is the fifth world's largest malignant tumor, which seriously endangers human health. The commonly used treatment effects are not satisfactory and the mortality rate is still high. Therefore, there is an urgent need for effective adjuvant treatment to improve patient survival. Alpha-fetoprotein (AFP) acts as the most common tumor marker used for HCC diagnosis. Studies have shown that alpha-fetoprotein can self-induce T cells in patients with hepatocellular carcinoma, and its immunogenic antigenic epitopes provide new ideas for the study of AFP vaccine. Presently, a variety of AFP vaccines have been developed, such as DC vaccine, DNA vaccine, and peptide vaccine, which have been successfully applied to HCC mouse model and phase I /II clinical trials, with evident results. This article discusses the molecular mechanism, categories and application prospects of AFP vaccine in HCC.

Enhanced Propulsion of Urease-Powered Micromotors by Multilayered Assembly of Ureases on Janus Magnetic Microparticles

Enzyme-powered micro/nanomotors propelled by biocompatible fuels generally show a weak propulsive force, which greatly limits their applications in complex biological environments. Herein, we have developed a novel and versatile approach to significantly enhance the propulsion of enzyme-powered micromotors by multilayered assembly of enzymes. As an example, multilayers of biotinylated ureases (BU) were asymmetrically immobilized on biotinylated Janus Au/magnetic microparticles (MMPs) with the assistance of streptavidin (SA). When the mass ratio of BU into SA and the amount of BU used in the assembly process are increased, the amount of urease immobilized on the biotinylated Janus Au/MMPs increased monotonously while the migration speed of the micromotor was augmented gradually until a saturated value. The as-optimized micromotors can be self-propelled with an average speed up to about 21.5 ± 0.8 μm/s at physiological urea concentrations (10 mM), which is five times faster than that of the monolayered counterparts and two times faster than that of the previously reported values. Owing to the enhanced thrust, the micromotors can move in liquids with viscosities similar to that of blood. In addition, with the inherent magnetic property of MMPs, the micromotors can exhibit fast magnetic separation and controllable motion direction by external magnetic fields. Our results provide a new pathway for designing high-efficient enzyme-powered micro/nanomotors and thereby promote their biomedical applications.

Metagenomic profiling of the pro-inflammatory gut microbiota in ankylosing spondylitis

OBJECTIVE

Gut dysbiosis has been reported implicated in ankylosing spondylitis (AS), a common chronic inflammatory disease mainly affects sacroiliac joints and spine. Utilizing deep sequencing on the feces of untreated AS patients, our study aimed at providing an in-depth understanding of AS gut microbiota.

METHODS

We analyzed the fecal metagenome of 85 untreated AS patients and 62 healthy controls by metagenomic shotgun sequencing, and 23 post-treatment feces of those AS patients were collected for comparison. Comparative analyses among different cohorts including AS, rheumatoid arthritis and Behcet's disease were performed to uncover some common signatures related to inflammatory arthritis. Molecular mimicry of a microbial peptide was also demonstrated by ELISpot assay.

RESULTS

We identified AS-enriched species including Bacteroides coprophilus, Parabacteroides distasonis, Eubacterium siraeum, Acidaminococcus fermentans and Prevotella copri. Pathway analysis revealed increased oxidative phosphorylation, lipopolysaccharide biosynthesis and glycosaminoglycan degradation in AS gut microbiota. Microbial signatures of AS gut selected by random forest model showed high distinguishing accuracy. Some common signatures related to autoimmunity, such as Bacteroides fragilis and type III secretion system (T3SS), were also found. Finally, in vitro experiments demonstrated an increased amount of IFN-γ producing cells triggered by a bacterial peptide of AS-enriched species, mimicking type II collagen.

CONCLUSIONS

These findings collectively indicate that gut microbiota was perturbed in untreated AS patients with diagnostic potential, and some AS-enriched species might be triggers of autoimmunity by molecular mimicry. Additionally, different inflammatory arthritis shared some common microbial signatures.

[Current status regarding the cardiovascular disease-related risk levels among the hypertensive population of different ethnicities in Xinjiang Uygur Autonomous Region, China]

OBJECTIVE

To assess the status of the cardiovascular disease associated risk levels among hypertensive population of Han, Uygur and Kazakh ethnicities, in Xinjiang Uygur Autonornous Region, to guide hypertension prevention and treatment in different ethnicities.

METHODS

Four stages random cluster sampling method was used, and all the data was collected from Xinjiang local residents aged over 18 between October 2007 and March 2010.

RESULTS

A total of 14 618 subjects completed this survey, in which 2 654 Han, 1 612 Uygur and 2034 Kazakh people diagnosed with hypertension was included in this research. Most of them were"grade 1 hypertension", and the percentage of grade 3 hypertension was Han (19.1%), Uygur (17.3%) and Kazakh (32.3%), respectively. Majority hypertensive people accompanied with 1 risk factor. The risk proportions of low, medium, high and very high in hypertension population of different ethnicities were Han (19.4%, 34.6%, 46.1%), Uygur (17.7%, 37.6%, 44.7%), Kazakh (12.5%, 38.0%, 49.4%) respectively. In Han, Uygur and Kazakh ethnicities, the percentage of high risk and very high risk was highest in hypertensive men aged over 60 years old.The percentages of hypertension awareness were 42.0%, 45.6%, 46.5% and percentages of medicine therapy were 29.6%, 23.4%, 25.2% for Han, Uygur and Kazakh ethnicities, respectively.

CONCLUSIONS

Hypertensive people among Han, Uygur and Kazakh ethnicities in Xinjiang are mainly under high risk and very high risk situation of cardiovascular disease, especially in men aged ≥60. The percentage of hypertension awareness and medicine therapy in high risk and very high risk population is the highest, while percentage of awareness in medium risk population is low.

Association of a transforming growth factor-β1 polymorphism with acute coronary syndrome in a Chinese Han population

Acute coronary syndrome (ACS) is a complex multifactorial and polygenic disorder that is thought to result from the interaction between an individual's genetic makeup and various environmental factors. The aim of this study was to investigate the association of a transforming growth factor-β1 (TGF-β1) polymorphism (-509C>T) with ACS in a Chinese Han population. The TGF-β1 polymorphism was evaluated in 336 patients with ACS and 396 healthy control subjects by polymerase chain reaction-restriction fragment length polymorphism. The genotype distributions of the control and ACS groups were in Hardy-Weinberg equilibrium (X(2) = 3.54 and X(2) = 1.72, respectively, P > 0.05). The frequencies of the CC, CT, and TT genotypes were 22.61, 53.57, and 20.83% in the ACS group, respectively, whereas they were 8.33, 48.74, and 42.17% in controls. There were significant differences between controls and ACS patients in the frequencies of the CC genotype and the C allele. These results suggest that the promoter polymorphism (-509C>T) in TGF-β1 is associated with ACS in this population. The CC genotype and the C allele of TGF-β1 might be a specific risk factor of ACS in the Chinese Han population in Xinjiang.

Role and influence of mycorrhizal fungi on radiocesium accumulation by plants

This review summarizes current knowledge on the contribution of mycorrhizal fungi to radiocesium immobilization and plant accumulation. These root symbionts develop extended hyphae in soils and readily contribute to the soil-to-plant transfer of some nutrients. Available data show that ecto-mycorrhizal (ECM) fungi can accumulate high concentration of radiocesium in their extraradical phase while radiocesium uptake and accumulation by arbuscular mycorrhizal (AM) fungi is limited. Yet, both ECM and AM fungi can transport radiocesium to their host plants, but this transport is low. In addition, mycorrhizal fungi could thus either store radiocesium in their intraradical phase or limit its root-to-shoot translocation. The review discusses the impact of soil characteristics, and fungal and plant transporters on radiocesium uptake and accumulation in plants, as well as the potential role of mycorrhizal fungi in phytoremediation strategies.

Impact of arbuscular mycorrhizal fungi on uranium accumulation by plants

Contamination by uranium (U) occurs principally at U mining and processing sites. Uranium can have tremendous environmental consequences, as it is highly toxic to a broad range of organisms and can be dispersed in both terrestrial and aquatic environments. Remediation strategies of U-contaminated soils have included physical and chemical procedures, which may be beneficial, but are costly and can lead to further environmental damage. Phytoremediation has been proposed as a promising alternative, which relies on the capacity of plants and their associated microorganisms to stabilize or extract contaminants from soils. In this paper, we review the role of a group of plant symbiotic fungi, i.e. arbuscular mycorrhizal fungi, which constitute an essential link between the soil and the roots. These fungi participate in U immobilization in soils and within plant roots and they can reduce root-to-shoot translocation of U. However, there is a need to evaluate these observations in terms of their importance for phytostabilization strategies.

Effects of the arbuscular mycorrhizal fungus Glomus mosseae on growth and metal uptake by four plant species in copper mine tailings

A greenhouse experiment was conducted to evaluate the potential role of arbuscular mycorrhizal fungi (AMF) in encouraging revegetation of copper (Cu) mine tailings. Two native plant species, Coreopsis drummondii and Pteris vittata, together with a turf grass, Lolium perenne and a leguminous plant Trifolium repens associated with and without AMF Glomus mosseae were grown in Cu mine tailings to assess mycorrhizal effects on plant growth, mineral nutrition and metal uptake. Results indicated that symbiotic associations were successfully established between G. mosseae and all plants tested, and mycorrhizal colonization markedly increased plant dry matter yield except for L. perenne. The beneficial impacts of mycorrhizal colonization on plant growth could be largely explained by both improved P nutrition and decreased shoot Cu, As and Cd concentrations. The experiment provided evidence for the potential use of local plant species in combination with AMF for ecological restoration of metalliferous mine tailings.

Influences of polycyclic aromatic hydrocarbons (PAHs) on soil microbial community composition with or without vegetation

Uptake of three polycyclic aromatic hydrocarbons (PAHs), naphthalene (NAP), phenanthrene (PHN), and pyrene (PYR), from soils by ryegrass, white clover and soybean were investigated in an 8-week pot experiment. The microbial phospholipid-fatty-acid (PLFA) patterns in PAHs-contaminated soil were analyzed. Contamination with PAHs inhibited the soil microbial activity. In non-vegetated soils, the total PLFA showed 87% reduction on the addition of PAHs after an 8-week incubation compared to the PAH-free soil; the concentrations of NAP, PHN, and PYR in soils showed 19.4%, 25.5% and 24.3% reduction, respectively, due mainly to the evaporative loss and microbial degradation. In vegetated soils, the reduction of added NAP and PHN levels was not related to the plant biomass nor to the total PLFA. However, the reduction in PYR concentrations in soil mediated by soybean growth was much pronounced than those by ryegrass or white clover growth, but thisis not related to the total microbial biomass as revealed by PLFAs. The principal-component analysis (PCA) of the PLFA signatures revealed significant changes in the PLFA pattern in PAH-spiked soils when different vegetations were planted. Using the PLFA as a biomarker, it was found that the Gram-negative bacteria were more sensitive to PAHs than Gram-positive bacteria and fungi.

Effects of arbuscular mycorrhizal inoculation on uranium and arsenic accumulation by Chinese brake fern (Pteris vittata L.) from a uranium mining-impacted soil

A glasshouse experiment was conducted to investigate U and As accumulation by Chinese brake fern, Pteris vittata L., in association with different arbuscular mycorrhizal fungi (AMF) from a U and As contaminated soil. The soil used contains 111 mg U kg(-1) and 106 mg As kg(-1). P. vittata L. was inoculated with each of three AMF, Glomus mosseae, Glomus caledonium and Glomus intraradices. Two harvests were made during plant growth (two and three months after transplanting). Mycorrhizal colonization depressed plant growth particularly at the early stages. TF (transfer factor) values for As from soil to fronds were higher than 1.0, while those for roots were much lower. Despite the growth depressions, AM colonization had no effect on tissue As concentrations. Conversely, TF values for U were much higher for roots than for fronds, indicating that only very small fraction of U was translocated to fronds (less than 2%), regardless of mycorrhizal colonization. Mycorrhizal colonization significantly increased root U concentrations at both harvests. Root colonization with G. mosseae or G. intraradices led to an increase in TF values for U from 7 (non-inoculation control) to 14 at the first harvest. The highest U concentration of 1574 mg kg(-1) was recorded in roots colonized by G. mosseae at the second harvest. The results suggested that P. vittata in combination with appropriate AMF would play very important roles in bioremediation of contaminated environments characterized by a multi-pollution.

Yield and arsenate uptake of arbuscular mycorrhizal tomato colonized by Glomus mosseae BEG167 in As spiked soil under glasshouse conditions

A glasshouse pot experiment was conducted to study the effect of arbuscular mycorrhizal (AM) colonization by Glomus mosseae BEG167 on the yield and arsenate uptake of tomato plants in soil experimentally contaminated with five As levels (0, 25, 50, 75 and 150 mg kg(-1)). Mycorrhizal colonization (50-70% of root length) was little affected by As application and declined only in soil amended with 150 mg As kg(-1). Mycorrhizal colonization increased plant biomass at As application rates of 25, 50 and 75 mg kg(-1). Shoot As concentration increased with increasing As addition up to 50 mg kg(-1) but decreased with mycorrhizal colonization at As addition rates of 75 and 150 mg kg(-1). Shoot As uptake increased with mycorrhizal colonization at most As addition levels studied, but tended to decrease with addition of 150 mg As kg(-1). Total P uptake by mycorrhizal plants was elevated at As rates of 25, 50 and 75 mg kg(-1), and more P was allocated to the roots of mycorrhizal plants. Mycorrhizal plants had higher shoot and root P/As ratios at higher As application rates than did non-mycorrhizal controls. The soil of inoculated treatments had higher available As than uninoculated controls, and higher pH values at As addition levels of 25, 50 and 75 mg kg(-1). Mycorrhizal colonization may have increased plant resistance to potential As toxicity at the highest level of As contamination studied. Mycorrhizal tomato plants may have potential for phytoextraction of As from moderately contaminated soils or phytostabilization of more highly polluted sites.

Influence of the arbuscular mycorrhizal fungus Glomus mosseae on uptake of arsenate by the As hyperaccumulator fern Pteris vittata L

We report for the first time some effects of colonization by an arbuscular mycorrhizal (AM) fungus (Glomus mosseae) on the biomass and arsenate uptake of an As hyperaccumulator, Pteris vittata. Two arsenic levels (0 and 300 mg As kg(-1)) were applied to an already contaminated soil in pots with two compartments for plant and hyphal growth in a glasshouse experiment. Arsenic application had little or no effect on mycorrhizal colonization, which was about 50% of root length. Mycorrhizal colonization increased frond dry matter yield, lowered the root/frond weight ratio, and decreased frond As concentration by 33-38%. Nevertheless, transfer of As to fronds showed a 43% increase with mycorrhizal colonization at the higher soil As level. Frond As concentrations reached about 1.6 g kg(-1) (dry matter basis) in non-mycorrhizal plants in the As-amended soil. Mycorrhizal colonization elevated root P concentration at both soil As levels and mycorrhizal plants had higher P/As ratios in both fronds and roots than did non-mycorrhizal controls.

Uptake of cadmium from an experimentally contaminated calcareous soil by arbuscular mycorrhizal maize (Zea mays L.)

We investigated uptake of Cd by arbuscular mycorrhizal (AM) maize inoculated with Glomus mosseae from a low-P sandy calcareous soil in two glasshouse experiments. Plants grew in pots containing two compartments, one for root and hyphal growth and one for hyphal development only. Three levels of Cd (0, 25 and 100 mg kg(-1)) and two of P (20 and 60 mg kg(-1)) were applied separately to the two compartments to assess hyphal uptake of Cd. Neither Cd nor P addition inhibited root colonization by the AM fungus, but Cd depressed plant biomass. Mycorrhizal colonization, P addition and increasing added Cd level led to lower Cd partitioning to the shoots. Plant P uptake was enhanced by mycorrhizal colonization at all Cd levels studied. When Cd was added to the plant compartment and P to the hyphal compartment, plant biomass increased with AM colonization and the mycorrhizal effect was more pronounced with increasing Cd addition. When P was added to the plant compartment and Cd to the hyphal compartment, plant biomass was little affected by AM colonization, but shoot Cd uptake was increased by colonization at the low Cd addition rate (25 mg kg(-1)) and lowered at the higher Cd rate (100 mg kg(-1)) but with no difference in root Cd uptake. These effects may have been due to immobilization of Cd by the fungal mycelium or effects of the AM fungus on rhizosphere physicochemical conditions and are discussed in relation to possible phytostabilization of contaminated sites by AM plants.

The role of arbuscular mycorrhiza in zinc uptake by red clover growing in a calcareous soil spiked with various quantities of zinc

Three pot experiments were conducted to investigate the role of arbuscular mycorrhiza (AM) in Zn uptake by red clover. Plants inoculated with Glomus mosseae and uninoculated controls were grown in a sterile calcareous soil in 'Plexiglas' (Acrylic) containers with two nylon net partitions (30 microm mesh) to separate the central root zone from the two outer hyphal zones. The effects of mycorrhiza on plant growth and Zn uptake changed dramatically with increasing Zn addition level (range 0-1200 mg kg(-1)) in the root zone. With Zn addition levels <300 mg kg(-1), added Zn did not affect plant yield and above the critical level plant yield gradually decreased but was always higher for mycorrhizal than for controls. Below the critical Zn application rate (50 mg kg(-1)), Zn uptake was enhanced while above this level Zn translocation to the shoots decreased. At all Zn addition levels, mycorrhizal colonization increased Zn absorption and accumulation in the roots, and this may help to explain the alleviation of Zn toxicity at high Zn application rates. As expected, AM colonization enhanced P nutrition and hence yield at all added Zn levels studied. Efforts were made to obtain direct evidence for hyphal contribution to Zn uptake by applying both Zn to the hyphal growth zone and additional P to the root zone to avoid the 'growth dilution effect'. The data demonstrate that mycorrhizal hyphae could absorb Zn directly from the soil and then transfer it to the plant roots. The hyphal contribution to Zn uptake by the host plant reached its maximum value at the Zn addition level of 50 mg kg(-1), in which Zn uptake via the extramatrical hyphae comprised 22% of total uptake, thus confirming the critical Zn application level found previously.

Appearance of shortened Bcl-2 and Bax proteins and lack of evidence for apoptosis in rat forebrain after severe experimental traumatic brain injury

To investigate whether apoptosis plays a role in traumatic brain injury (TBI), we examined the expression of Bcl-2 and Bax proteins and the release of mitochondrial cytochrome c in rat brains using Western blot analysis. Bcl-2 at the predicted 26 kDa was not detected in controls and TBI groups. However, at 1 h post-TBI, a shortened Bcl-2 protein with a molecular size of approximately 14.5 kDa was detected in the injured hemisphere (R). At 4 and 12 h post TBI, an additional bcl-2 band ( approximately 10 kDa) was detected in R. Both bands disappeared at 14 days post-injury. The predicted 21-kDa band of Bax was detected in both controls and TBI animals. In addition, two shortened Bax proteins ( approximately 18 kDa) were detected after TBI. The time course of appearance was similar to that of Bcl-2 described above. In the present study, neither cytochrome c release from mitochondria nor DNA fragmentation was detected in the forebrains of sham and TBI groups. Treatment of animals with an antioxidant N-acetylcysteine administered ip greatly diminished the levels of shortened Bcl-2 and Bax proteins. These findings suggest that the induction of shortened Bcl-2 and Bax proteins in rat brains may be associated with reactive oxygen species generated after TBI.

Resistance of bone marrow-derived macrophages to apoptosis is associated with the expression of X-linked inhibitor of apoptosis protein in primary cultures of bone marrow cells

In this study we investigated the underlying mechanisms that confer resistance on mature macrophages with the use of macrophage colony-stimulating factor (M-CSF)-induced bone marrow-derived macrophages (BMDM). In the presence of M-CSF, immature precursor cells were induced to undergo proliferation and differentiation into mature macrophages in vitro with cell morphology similar to that of tissue macrophages by day 7-10. Immunoblot analyses showed that bone marrow precursors express appreciable levels of caspase-3 and caspase-9 but no or very low levels of c-fms (M-CSF receptor) and the apoptosis regulators X-linked inhibitor of apoptosis protein (XIAP), c-IAP-1, Bcl-2 and Bax. The differentiation of BMDM is associated with a steady and gradual increase in the levels of c-fms, XIAP, c-IAP-1, Bcl-2 and Bax, reaching maximal levels by day 7. However, the levels of caspase-3 and caspase-9 stayed essentially unchanged even after prolonged incubation (more than 10 days) with M-CSF. Unlike bone marrow precursor cells, mature BMDM (day 7-10) were resistant to apoptosis induced by M-CSF depletion, which includes the activation of caspase-3 and caspase-9 and the degradation of XIAP, Bcl-2 and Bax proteins in the process. Treatment of day 7 BMDM with XIAP anti-sense oligonucleotides (oligos), but not sense oligos, partly abolished their resistance to apoptosis. By using a gel-shift assay and a specific nuclear factor kappaB (NF-kappaB) inhibitor, we demonstrated that NF-kappaB activity is responsible for the up-regulation of XIAP in M-CSF-treated macrophages. In addition, treatment of starved macrophages with M-CSF induced a rapid phosphorylation of Akt kinase before the activation of NF-kappaB. Our results showed that XIAP is one of the anti-apoptotic regulators that confer resistance on mature macrophages by M-CSF.

Apoptosis of Mo7e leukemia cells is associated with the cleavage of Bcl-2 into a shortened fragment that is not functional for heterodimerization with Bcl-2 and Bax

Bcl-2 is an integral intracellular membrane protein that can protect cells from apoptosis induced by multiple insults in a variety of cell types. During apoptosis, Bcl-2 was cleaved into a shortened fragment (Bcl-2/Delta34) by a caspase-3-like protease in human Mo7e megakaryocytic leukemia cells deprived of exogenous rhGM-CSF. Results from cell fractionation and immunoblot analyses indicated that both Bcl-2 and Bcl-2/Delta34 were located exclusively on the mitochondria of Mo7e cells. Treatment of isolated mitochondria with recombinant caspase-3 induced the same cleavage of Bcl-2 in vitro and caused the release of cytochrome c from the mitochondria into the supernatant. The antiapoptotic effect of Bcl-2/Delta34 was investigated using an in vitro protein translation approach. Both Bcl-2/Delta34 and Bax proteins generated in wheat germ extract were readily relocated to the mitochondria isolated from control Mo7e cells. Insertion of Bax, but not Bcl-2/Delta34, into mitochondria triggered a rapid release of cytochrome c from the mitochondria. Coimmunoprecipitation studies showed that, unlike Bcl-2, the cleaved Bcl-2 fragment was no longer functional for dimerization with either Bcl-2 or Bax. Taken together, these findings showed that the integrity of Bcl-2 is necessary for its function of heterodimerization with Bax, which appears to be one of the mechanisms of antiapoptotic effect of Bcl-2.

Human THP-1 monocytic leukemic cells induced to undergo monocytic differentiation by bryostatin 1 are refractory to proteasome inhibitor-induced apoptosis

The ubiquitin-proteasome pathway is the principal mechanism for the degradation of short-lived proteins in eukaryotic cells. We demonstrated that treatment of THP-1 human monocytic leukemia cells with Z-LLL-CHO, a reversible proteasome inhibitor, induced cell death through an apoptotic pathway. Apoptosis in THP-1 cells induced by Z-LLL-CHO involved a cytochrome c-dependent pathway, which included the release of mitochondrial cytochrome c, activation of caspase-9 and -3, and cleavage of Bcl-2 into a shortened 22-kDa fragment. Induction of apoptosis by protease inhibitor also was detected in U937 and TF-1 leukemia cell lines and cells obtained from acute myelogenous leukemia patients but not in normal human blood monocytes. Treatment of human blood monocytes with Z-LLL-CHO did not induce apoptosis or Bcl-2 cleavage in these cells that rarely proliferate. Interestingly, when THP-1 cells were induced to undergo monocytic differentiation by bryostatin 1, a naturally occurring protein kinase C activator, they were no longer susceptible to apoptosis induced by Z-LLL-CHO. Bryostatin 1-induced differentiation of THP-1 cells was associated with growth arrest, acquisition of adherent capacity, and expression of membrane markers characteristic of blood monocytes. Likewise, differentiated THP-1 cells were refractory to Z-LLL-CHO-induced cytochrome c release, caspase activation, and Bcl-2 cleavage. Resistance to Z-LLL-CHO-induced apoptosis in differentiated THP-1 cells was not due to cell cycle arrest. These findings show that the action of proteasome inhibitors is mediated primarily through a cytochrome c-dependent pathway and induces apoptosis in leukemic cells that are not differentiated.

Bcl-2 antibodies induce hemoglobin release by red blood cells loaded with in vitro translated Bcl-2 and its cleaved fragment

Apoptosis induced by proteasome inhibitor in human THP-1 leukemia cells is associated with the cleavage of Bcl-2 into a shortened fragment, Bcl-2/Delta34. Both Bcl-2 and its cleaved fragment were located exclusively on the mitochondria of THP-1 cells. No translocation of Bcl-2 or Bcl-2/Delta34 to the cytosolic fraction was detected during apoptosis. Treatment of isolated mitochondria with recombinant caspase-3 induced the same cleavage of Bcl-2 in vitro and triggered the release of cytochrome c from the mitochondria. The ability of Bcl-2/Delta34 in regulating the opening of membrane "pores" was investigated using a sheep red blood cell (RBC) model with in vitro translated Bcl-2/Delta34 and Bcl-2 proteins. Bcl-2 and Bcl-2/Delta34 generated in vitro were relocated rapidly to sheep RBC but caused no hemoglobin release in either case. Addition of anti-Bcl-2 antibodies directly to the RBC that had been loaded with either Bcl-2 or Bcl-2/Delta34 resulted in a rapid release of hemoglobin from the blood cells. Treatment of the sheep RBC with anti-Bcl-2 or anti-sheep RBC antibodies alone did not trigger hemoglobin release from the RBC. Based on these findings, we proposed that, upon "enforced aggregation," both Bcl-2 and Bcl-2/Delta34 can form "pores" in membranes, which may contribute to the release of cytochrome c in apoptosis.

Inhibition of ubiquitin-proteasome pathway activates a caspase-3-like protease and induces Bcl-2 cleavage in human M-07e leukaemic cells

The ubiquitin-proteasome pathway is the principal mechanism for the degradation of short-lived proteins in eukaryotic cells. Here we examine the possibility that ubiquitin-proteasome is involved in regulating the levels of Bcl-2, which is abundantly expressed in M-07e cells, a granulocyte/macrophage colony-stimulating factor (GM-CSF)-dependent human leukaemic cell line. Apoptosis in M-07e cells, induced by GM-CSF withdrawal, was associated with a gradual cleavage of Bcl-2 into a 22 kDa fragment. Treatment of M-07e cells with benzyloxycarbonyl-Leu-Leu-l-leucinal (Z-LLL-CHO; MG-132), a reversible ubiquitin-proteasome inhibitor, markedly accelerated the cleavage of Bcl-2 and promoted cell death through the apoptotic pathway. The cleavage of Bcl-2 was inhibited by a caspase-3 (CPP32)-specific inhibitor [acetyl-Asp-Glu-Val-Asp-CHO (DEVD-CHO)] but not caspase 1 inhibitor (acetyl-Tyr-Val-Ala-Asp-CHO), suggesting that Bcl-2 is a proteolytic substrate of a caspase-3-like protease activated during apoptosis. The simultaneous addition of recombinant human GM-CSF (rhGM-CSF) to M-07e cultures delayed the activation of caspase 3 and Bcl-2 cleavage triggered by Z-LLL-CHO, suggesting that the activation of the GM-CSF signalling pathway can partly overcome the apoptotic effect induced by Z-LLL-CHO. Apoptosis induced by inhibition of the proteasome pathway was verified in studies with lactacystin, a highly specific and irreversible proteasome inhibitor. Lactacystin-induced apoptosis in M-07e cells was remarkably similar to that induced by Z-LLL-CHO, which included caspase 3 activation, cleavage of Bcl-2 into a 22 kDa fragment and, ultimately, cell death. These results showed that inhibition of the ubiquitin-proteasome pathways can lead to the activation of a DEVD-CHO-sensitive caspase and induces Bcl-2 cleavage, which might have a role in mediating apoptosis in M-07e cells.

Cellular uptake of a novel cytotoxic agent, cryptophycin-52, by human THP-1 leukemia cells and H-125 lung tumor cells

Cryptophycin (CP) is a newly developed anticancer agent isolated from the terrestrial cyanobacteria of the genus Nostoc. CP is a mitotic inhibitor, causing cells to accumulate in mitosis with the disappearance of intracellular microtubules. In this report, we studied the interaction and uptake of a new synthetic CP analog, CP-52, with 2 human tumor cell lines, THP-1 and H-125. In vitro colony-forming assay showed that CP-52 has antiproliferative activity against THP-1 and H-125 cell lines with IC50 of 0.1 ng/ml and 20 microg/ml, respectively; i.e., THP-1 cells are 200,000 times more sensitive to CP-52 than H-125 cells. The uptake of CP-52 by the target cells was carried out using tritiated CP-52 (3H-CP-52). The uptake of 3H-CP-52 by both THP-1 and H-125 cells was rapid, reaching a maximum within 20 min. Dissociation experiments showed that CP-52 interacts with the target cells irreversibly, presumably by binding to specific cellular sites with high affinity. With increasing doses of 3H-CP-52, the uptake was found to be saturable, reaching a steady state as the concentrations of 3H-CP-52 were raised to about 20 microg/ml. Under this condition, the maximal values of CP-52 uptake by THP-1 and H-125 cells was estimated to be 27 and 136 ng/10(5) cells, respectively. The uptake and accumulation of 3H-CP-52 with the target cells was effectively inhibited by prior treatment with unlabeled CP-52 and, to a lesser extent, vinblastine and taxol but not adriamycin, colchicine or mitomycin. In addition, the binding of 3H-CP-52 to purified tubulin was inhibited by vinblastine but not taxol. This finding suggested that CP-52 and taxol interact and bind to distinct regions of tubulin molecules. Further, it suggests that, in addition to tubulin, other intracellular and/or membrane components are involved in mediating the binding of CP-52.

Phase I study of bryostatin 1 in patients with relapsed non-Hodgkin's lymphoma and chronic lymphocytic leukemia

PURPOSE

To define, in a phase I study in relapsed non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL), the maximum-tolerated dose (MTD), major toxicities, and possible antitumor activity of bryostatin 1, a macrocyclic lactone.

PATIENTS AND METHODS

Bryostatin 1 was delivered by 72-hour continuous infusion every 2 weeks to patients with relapsed NHL or CLL, at doses that ranged from 12 microg/m2 to 180 microg/m2 per course. Correlative investigations included evaluations of total protein kinase C (PKC) in peripheral blood and lymphoid differentiation in patient tumor tissue.

RESULTS

Twenty-nine patients were treated, including three patients with CLL and 26 with NHL. Generalized myalgia was the dose-limiting toxicity (DLT) and occurred in two of three patients treated with bryostatin 1 at 180 microg/m2 per course. Myalgias were dose-related and cumulative, and often started in the thighs and calves, improved with activity, were somewhat responsive to analgesics, and often took weeks to resolve once taken off study. Six patients were treated at the MTD of 120 microg/m2 per course. Myalgia, headache, and fatigue were common. Hematologic toxicity was uncommon. Total cumulative doses of bryostatin 1 up to 1,134 microg/m2 have been administered without untoward toxicity. Eleven patients achieved stable disease for 2 to 19 months. An in vitro assay for total PKC evaluation in patient peripheral-blood samples demonstrated activation within the first 2 hours with subsequent downregulation by 24 hours, which was maintained throughout the duration of the 72-hour infusion.

CONCLUSION

This phase I study defined the MTD and recommended phase II dose of bryostatin 1, when administered over 72 hours every 2 weeks, to be 120 microg/m2 (40 microg/m2/d for 3 days). Generalized myalgia was the DLT. Future studies will define the precise activity of bryostatin 1 in subsets of patients with lymphoproliferative malignancies and its efficacy in combination with other agents.

Enhancement of J6-1 human leukemic cell proliferation by membrane-bound M-CSF through a cell-cell contact mechanism II. Role of an M-CSF receptor-like membrane protein

We have isolated an M-CSF-like membrane-associated growth factor from human leukemic J6-1 cells that can enhance the growth and colony formation of J6-1 cells in vitro. Indirect evidence suggests that this membrane-associated M-CSF-like growth factor may do so by stimulating a corresponding receptor co-expressed on the adjacent J6-1 cells. The objective of this study is to isolate the putative receptor in J6-1 cells by virtue of its ability to bind and thus "block" the growth of J6-1 cells. Based on this approach, we have isolated from the J6-1 cell membrane an inhibitory activity that can inhibit the clonal growth of J6-1 cells. The activity of this inhibitor can be readily neutralized by either anti-M-CSFR MAb or anti-M-CSFR antiserum, suggesting that it is related to M-CSFR, a product of c-fms proto-oncogene. Judging from Sephadex G-200 gel filtration, the molecular weight (MW) of this putative M-CSFR-like inhibitor was estimated to be approx. 150-180 kDa, comparable with that of M-CSFR. The specificity of M-CSFR-like protein to recognize and block membrane-bound M-CSF also was implicated by its ability to upregulate the steady-state levels of c-fms mRNA in J6-1 cells. Besides its antiproliferative activity in vitro, treatment of J6-1 cells with the putative receptor protein before inoculation effectively blocked the growth and tumor formation in vivo by J6-1 cells in a nude mouse model. These findings suggest that the growth and tumor development by J6-1 leukemic cells may involve a contact-mediated "juxtacrine mechanism".

Enhancement of J6-1 human leukemic cell proliferation by cell-cell contact: role of an M-CSF-like membrane-associated growth factor MAF-J6-1

Density-dependent cell proliferation and cluster formation are growth phenotypes frequently associated with leukemia cells. The secretion of autocrine growth factor, such as granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 1 (IL-1), has been implicated as one possible mechanism in leukemogenesis. In many cases, however, leukemia cells do not appear to produce autocrine growth stimulators. J6-1 is an established human myeloid leukemia cell line that exhibits both density-dependent and cluster-forming growth characteristics. The effect of direct cell-cell contact on J6-1 cell proliferation was investigated. We have isolated from J6-1 cells a membrane-bound factor (designated as MAF-J6-1) that promoted the colony formation by both J6-1 cells and mouse bone marrow CFU-GM. The growth-promoting activity of MAF-J6-1 can be neutralized by either anti-macrophage-CSF (M-CSF or CSF-1) or anti-MAF-J6-1 monoclonal antibodies (MAb), suggesting that MAF-J6-1 is related to M-CSF. Using an immunoblot analysis with anti-MAF-J6-1 MAb, the MW of this membrane-associated factor was estimated to be 80 kDa. Both antibodies also induced a modest growth inhibition on J6-1 cells in vitro. Similarly, addition of exogenous recombinant human M-CSF augmented the colony formation by J6-1 cells, an effect also neutralized by both antibodies. Using an in situ hybridization technique, J6-1 cells were found to express a high level of c-fms proto-oncogene, which encodes the receptor for the M-CSF. Taken together, our results suggest that the membrane-bound MAF-J6-1 promote J6-1 cell proliferation and cluster formation through a 'juxtacrine' mechanism.

Downregulation of M-CSF receptors by lipopolysaccharide in murine peritoneal exudate macrophages is mediated through a phospholipase C dependent pathway

Murine peritoneal exudate macrophages (PEM) co-express granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage CSF (M-CSF) receptors, among others. Treatment of PEM with lipopolysaccharide (LPS) or tumor-promoting phorbol ester (12-O-tetradecanoylphorbol-13-acetate [TPA]) induces a rapid but transient loss of M-CSF receptors in PEM. GM-CSF receptors are not affected by this treatment. The loss of M-CSF receptors induced by LPS can be inhibited by neomycin and compound 48/80, two potent phospholipase C (PLC) inhibitors, but not by phospholipase A2, calpain, protein kinase C (PKC) or protease inhibitors. On the other hand, the loss of M-CSF receptors induced by TPA has been prevented by PKC inhibitors but not by PLC inhibitors. PLC inhibitors also prevent LPS-suppressed receptor-mediated internalization of radiolabeled recombinant human (rh) M-CSF by macrophages. Similar prevention of LPS-induced M-CSF receptor downregulation was observed in human monocytes that had been pretreated with PLC inhibitors. Our results show that 1) TPA-induced M-CSF receptor loss is strictly dependent on PKC activation; 2) PLC activation alone also leads to downregulation of M-CSF receptors; and 3) LPS-induced M-CSF receptor downregulation in PEM is mediated primarily through a PLC-dependent pathway. Our data also imply that the expression of M-CSF but not GM-CSF receptors is linked to an important, yet unknown, PLC-sensitive component(s) whose hydrolysis may lead to downregulation of M-CSF receptors.

Deregulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor in murine macrophage cell line J774A.1

J774A.1 immortalized macrophage tumor cells display several phenotypes and functional capacities similar to that of murine peritoneal exudate macrophages (PEM). Both populations display comparable number of M-CSF receptors. Yet the number of GM-CSF receptors on J774A.1 cells is only one-fourth that of PEM (1,500 vs. 6,000 per cell). Unlike J774A.1 cells, which constitutively express c-myc transcripts, normal PEM required rMuGM-CSF for the induction of c-myc expression. Nevertheless, the growth of J774A.1 cells can be further enhanced in the presence of exogenous rMuGM-CSF, rHuM-CSF, and rMuIL-3. Treatment with either rMuIL-3 (20 ng/ml) and rHuTGF-beta 1 (1.0 ng/ml) for 24 hr at 37 degrees C, markedly enhanced the expression of GM-CSF receptors on normal PEM but not leukemic J774A.1 cells. J774A.1 cells also did not respond by autologous upregulation of GM-CSF receptors as seen in PEM following treatment with rMuGM-CSF. Treatment with either pertussis toxin (20-100 ng/ml) or H-8 (50 microM) for 24 hr led to an enhanced expression of GM-CSF receptors on J774A.1 cells in a time- and dose-dependent manner but did not result in enhanced receptor expression on normal PEM. These findings suggest that the expression of GM-CSF receptors may be regulated by mechanisms involving Gi-proteins and their downstream elements, which in turn are linked to regulatory pathways of other cytokine receptors. In J774A.1 cells, such regulatory interaction may not exist.

Up-regulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors in murine peritoneal exudate macrophages by both GM-CSF and IL-3

Murine peritoneal exudate macrophages (PEM) display multiple CSF receptors. In this study, the expression of granulocyte-macrophage (GM)-CSF receptors in PEM was studied. PEM displayed over 5000 single type, high affinity GM-CSF receptors/cell with a Kd = 38 to 42 pM and an apparent molecular mass of 86,000 Da. Treatment of PEM with low, but not high, concentrations of recombinant murine (rMu) GM-CSF continuously for 24 h resulted in a marked up-regulation of GM-CSF receptors in PEM. A similar up-regulation of GM-CSF receptors also was detected in PEM cultures treated with rMuIL-3 (1-100 ng/ml) for 24 h or longer, regardless the doses of rMuIL-3 added in this case. Scatchard analysis of equilibrium binding showed that the enhanced binding activities in both cases were due to an increase in total number of GM-CSF receptors rather than changes in receptor affinity. Contrariwise, treatment with recombinant human macrophage-CSF (greater than 100-1000 ng/ml) partially inhibited the expression of GM-CSF receptors in PEM. Removal of rMuGM-CSF from culture medium 24 h after treatment led to a further up-regulation of GM-CSF receptors over a 4 to 24-h period, depending on the doses of initial treatment. On the other hand, removal of rMuIL-3 from culture medium after prolonged treatment did not result in further increase in GM-CSF receptors. The protein synthesis inhibitor cycloheximide abrogated GM-CSF receptor up-regulation induced by both rMuIL-3 and rMuGM-CSF, whereas actinomycin D inhibited only the second (8-24 h) phase of GM-CSF receptor up-regulation induced by exposure to high concentrations rMuGM-CSF (10 ng/ml). These findings suggest that rMuGM-CSF and rMuIL-3 up-regulate GM-CSF receptors in PEM in part through similar or identical metabolic pathways and provide further evidence of a close linkage between IL-3 and GM-CSF receptors.

Up-regulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors in murine peritoneal exudate macrophages by both GM-CSF and IL-3

Murine peritoneal exudate macrophages (PEM) display multiple CSF receptors. In this study, the expression of granulocyte-macrophage (GM)-CSF receptors in PEM was studied. PEM displayed over 5000 single type, high affinity GM-CSF receptors/cell with a Kd = 38 to 42 pM and an apparent molecular mass of 86,000 Da. Treatment of PEM with low, but not high, concentrations of recombinant murine (rMu) GM-CSF continuously for 24 h resulted in a marked up-regulation of GM-CSF receptors in PEM. A similar up-regulation of GM-CSF receptors also was detected in PEM cultures treated with rMuIL-3 (1-100 ng/ml) for 24 h or longer, regardless the doses of rMuIL-3 added in this case. Scatchard analysis of equilibrium binding showed that the enhanced binding activities in both cases were due to an increase in total number of GM-CSF receptors rather than changes in receptor affinity. Contrariwise, treatment with recombinant human macrophage-CSF (greater than 100-1000 ng/ml) partially inhibited the expression of GM-CSF receptors in PEM. Removal of rMuGM-CSF from culture medium 24 h after treatment led to a further up-regulation of GM-CSF receptors over a 4 to 24-h period, depending on the doses of initial treatment. On the other hand, removal of rMuIL-3 from culture medium after prolonged treatment did not result in further increase in GM-CSF receptors. The protein synthesis inhibitor cycloheximide abrogated GM-CSF receptor up-regulation induced by both rMuIL-3 and rMuGM-CSF, whereas actinomycin D inhibited only the second (8-24 h) phase of GM-CSF receptor up-regulation induced by exposure to high concentrations rMuGM-CSF (10 ng/ml). These findings suggest that rMuGM-CSF and rMuIL-3 up-regulate GM-CSF receptors in PEM in part through similar or identical metabolic pathways and provide further evidence of a close linkage between IL-3 and GM-CSF receptors.

Murine recombinant IL-4 is a bifunctional regulator of macrophage growth induced by colony-stimulating factors

Murine peritoneal exudate macrophage (PEM) coexpress receptors for both granulocyte-macrophage CSF (GM-CSF) and macrophage CSF (M-CSF) and can be induced by both factors, either alone or in combination, to undergo extensive proliferation in vitro. In this study the effect of murine rIL-4 (MurIL-4) on the proliferation of PEM was examined. MurIL-4 alone did not support macrophage proliferation but prolonged their survival in vitro. When MurIL-4 was combined with human (Hu)rM-CSF, it enhanced the proliferative response of PEM to rHuM-CSF in a dose-dependent manner, reaching a maximum at approximately 10 ng/ml. Contrarily, MurIL-4 suppressed the proliferative response of PEM to MurGM-CSF. Receptor binding assays using radiolabeled ligands showed that MurIL-4 selectively enhanced the expression of M-CSF receptors; suggesting that at least part of the synergistic effect of MurIL-4 is mediated at the receptor level. Of relevance to this effect is the finding that MurIL-4 greatly promoted the responsiveness of PEM to low concentrations of HurM-CSF. Unlike M-CSF receptors, however, MurIL-4 treatment failed to modulate the levels of GM-CSF receptors in PEM. The proliferative responses of PEM to both MurGM-CSF and HurM-CSF could be inhibited by MurIFN-gamma with similar sensitivity. This inhibitory effect of MurIFN-gamma was partially neutralized by MurIL-4 in cultures containing HurM-CSF but not those containing MurGM-CSF. This study demonstrates that IL-4 is involved directly in the regulation of macrophage production by modulating their responsiveness to various cytokines.

Murine recombinant IL-4 is a bifunctional regulator of macrophage growth induced by colony-stimulating factors

Murine peritoneal exudate macrophage (PEM) coexpress receptors for both granulocyte-macrophage CSF (GM-CSF) and macrophage CSF (M-CSF) and can be induced by both factors, either alone or in combination, to undergo extensive proliferation in vitro. In this study the effect of murine rIL-4 (MurIL-4) on the proliferation of PEM was examined. MurIL-4 alone did not support macrophage proliferation but prolonged their survival in vitro. When MurIL-4 was combined with human (Hu)rM-CSF, it enhanced the proliferative response of PEM to rHuM-CSF in a dose-dependent manner, reaching a maximum at approximately 10 ng/ml. Contrarily, MurIL-4 suppressed the proliferative response of PEM to MurGM-CSF. Receptor binding assays using radiolabeled ligands showed that MurIL-4 selectively enhanced the expression of M-CSF receptors; suggesting that at least part of the synergistic effect of MurIL-4 is mediated at the receptor level. Of relevance to this effect is the finding that MurIL-4 greatly promoted the responsiveness of PEM to low concentrations of HurM-CSF. Unlike M-CSF receptors, however, MurIL-4 treatment failed to modulate the levels of GM-CSF receptors in PEM. The proliferative responses of PEM to both MurGM-CSF and HurM-CSF could be inhibited by MurIFN-gamma with similar sensitivity. This inhibitory effect of MurIFN-gamma was partially neutralized by MurIL-4 in cultures containing HurM-CSF but not those containing MurGM-CSF. This study demonstrates that IL-4 is involved directly in the regulation of macrophage production by modulating their responsiveness to various cytokines.