Phenylethanoid glycosides (PhGs), a class of polyphenolic compounds, are considered one of major bioactive constituents of Cistanche deserticola Y.C. Ma (CD), whose extract is orally used in traditional Chinese medicine. Although previous pharmacological studies have reported that PhGs exert many activities, their intestinal transport profiles have not been clarified. In this study, we investigated the intestinal permeability of a PhG-rich extract (PRE) from CD as an integrated system in the Caco-2 cell monolayer model using a bioassay system. The results showed that PRE is primarily transported via poorly absorbed passive diffusion down a concentration gradient without efflux, which provides the pharmacokinetic basis for the clinical application of PhGs in CD. We also determined the intestinal permeability of three major PhGs [acteoside (AC), isoacteoside (IS) and echinacoside (EC)] by HLPC. Furthermore, we developed a novel HPLC-fluorescence detection method to accurately determine the flux amount of AC and IS. As expected, the transport characteristics of the three PhGs are consistent with those of PRE, indicating that the present bioassay system is appropriate and reliable for the evaluation of the transport characteristics of active ingredient groups (AIG) in PRE. Moreover, this system may also be suitable for other plant extracts given appropriate bioactivity.
The isolation and structural elucidation of a new tetracyclic polyketide (ruthmycin) from Streptomyces sp. RM-4-15, a bacteria isolated near thermal vents from the Ruth Mullins underground coal mine fire in eastern Kentucky, is reported. In comparison to the well-established frenolicin core scaffold, ruthmycin possesses an unprecedented signature C3 bridge and corresponding fused six member ring. Preliminary in vitro antibacterial, anticancer and antifungal assays revealed ruthmycin to display moderate antifungal activity.
Maintaining mitochondrial function is essential for neuronal survival and offers protection against neurodegeneration. Ubiquitin-mediated, proteasome-dependent protein degradation in the form of outer mitochondrial membrane associated degradation (OMMAD) was shown to play roles in maintenance of mitochondria on the level of proteostasis, but also mitophagy and cell death. Recently, the AAA-ATPase p97/VCP/Cdc48 was recognized as part of OMMAD acting as retrotranslocase of ubiquitinated mitochondrial proteins for proteasomal degradation. Thus, p97 likely plays a major role in mitochondrial maintenance. Support for this notion comes from mitochondrial dysfunction associated with amyotrophic lateral sclerosis and hereditary inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD) caused by p97 mutation. Using SH-SY5Y cells stably expressing p97 or dominant-negative p97QQ treated with mitochondrial toxins rotenone, 6-OHDA, or Aβ-peptide as model for neuronal cells suffering from mitochondrial dysfunction, we found mitochondrial fragmentation under normal and stress conditions was significantly increased upon inactivation of p97. Furthermore, inactivation of p97 resulted in loss of mitochondrial membrane potential and increased production of reactive oxygen species (ROS). Under additional stress conditions, loss of mitochondrial membrane potential and increased ROS production was even more pronounced. Loss of mitochondrial fidelity upon inactivation of p97 was likely due to disturbed maintenance of mitochondrial proteostasis as the employed treatments neither induced mitophagy nor cell death. This was supported by the accumulation of oxidatively-damaged proteins on mitochondria in response to p97 inactivation. Dysfunction of p97 under normal and stress conditions in neuron-like cells severely impacts mitochondrial function, thus supporting for the first time a role for p97 as a major component of mitochondrial proteostasis.
mitochondria; p97/VCP; neuronal cells; quality control
Cocaine is one of the most addictive drugs, and there is still no FDA (Food and Drug Administration)-approved medication specific for cocaine. A promising therapeutic strategy is to accelerate cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. cocaine hydrolysis catalyzed by butyrylcholinesterase (BChE), in plasma. However, the native BChE has a low catalytic efficiency against the abused cocaine, i.e. (−)-cocaine. Our recently designed and discovered A199S/F227A/S287G/A328W/Y332G mutant and other mutants of human BChE have a considerably improved catalytic efficiency against (−)-cocaine. In the present study, we carried out both computational modeling and experimental kinetic analysis on the catalytic activities of these promising new BChE mutants against other known substrates, including neurotransmitter acetylcholine (ACh), acetylthiocholine (ATC), butyrylthiocholine (BTC), and (+)-cocaine, in comparison with the corresponding catalytic activity against (−)-cocaine. Both the computational modeling and kinetic analysis have consistently revealed that all of the examined amino-acid mutations only considerably improve the catalytic efficiency of human BChE against (−)-cocaine, without significantly improving the catalytic efficiency of the enzyme against anyone of the other substrates examined. In particular, all of the examined BChE mutants have an even slightly lower catalytic efficiency against neurotransmitter ACh compared to the wild-type BChE. This observation gives us confidence in development of an anti-cocaine enzyme therapy by using one of these BChE mutants, particularly the A199S/F227A/S287G/A328W/Y332G mutant.
Proteasome is the major component of the crucial nonlysosomal protein degradation pathway in the cells, but the detailed reaction pathway is unclear. In this study, first-principles quantum mechanical/molecular mechanical free energy calculations have been performed to explore, for the first time, possible reaction pathways for proteasomal proteolysis/hydrolysis of a representative peptide, succinyl-leucyl-leucyl-valyl-tyrosyl-7-amino-4-methylcoumarin (Suc-LLVY-AMC). The computational results reveal that the most favorable reaction pathway consists of six steps. The first is a water-assisted proton transfer within proteasome, activating Thr1-Oγ. The second is a nucleophilic attack on the carbonyl carbon of a Tyr residue of substrate by the negatively charged Thr1-Oγ, followed by the dissociation of the amine AMC (third step). The fourth step is a nucleophilic attack on the carbonyl carbon of the Tyr residue of substrate by a water molecule, accompanied by a proton transfer from the water molecule to Thr1-Nz. Then, Suc-LLVY is dissociated (fifth step), and Thr1 is regenerated via a direct proton transfer from Thr1-Nz to Thr1-Oγ. According to the calculated energetic results, the overall reaction energy barrier of the proteasomal hydrolysis is associated with the transition state (TS3b) for the third step involving a water-assisted proton transfer. The determined most favorable reaction pathway and the rate-determining step have provided a reasonable interpretation of the reported experimental observations concerning the substituent and isotopic effects on the kinetics. The calculated overall free energy barrier of 18.2 kcal/mol is close to the experimentally-derived activation free energy of ~18.3–19.4 kcal/mol, suggesting that the computational results are reasonable.
Proteasome; proteolytic mechanism; QM/MM; peptide hydrolysis
To evaluate safety and efficacy of laparoscopy-assisted radical gastrectomy (LARG) for advanced gastric cancer patients aged 70 years or older. Clinical data were retrospectively collected from patients with IIA-IIIC gastric cancer who underwent LARG (n = 30) and open radical gastrectomy (ORG, n = 34) in Department of Gastrointestinal Surgery in the Ningbo First Hospital from January 2012 to December 2013. The mean operative time was longer in the LARG group than in the ORG group but there was no statistical difference between the two groups. The intraoperative blood loss (120 ± 52.7 ml vs 227.3 ± 146.9 ml), incidence of postoperative complication (23.0% vs 47%) were lower in the LARG group than those in the ORG group. In addition, the time to first flatus (2.9 ± 0.8 d vs 4.6 ± 1.2 d), time to first ambulation (1.2 ± 0.4 vs 4.1 ± 1.0 d), time of nasogastric intubation (2.5 ± 1.0 d vs 3.5 ± 1.4 d), and postoperative hospital stay (13.0 ± 4.2 d vs 16.9 ± 4.1 d) were significantly shorter in the LARG group than in the ORG group, respectively. No statistical difference in the number of harvested lymph nodes was noted between the two groups (30.2 ± 12.0 vs 28.1 ± 11.8, P > 0.05). LARG is safer, more effective and less invasive for the elderly patients with advanced gastric cancer.
Laparoscopy-assisted gastrectomy; open gastrectomy; gastric cancer; clinical efficacy
The purpose of the study was to measure the retinal venous pressure (RVP) in the eyes of primary open-angle glaucoma (POAG) patients and healthy subjects with and without a Flammer-Syndrome (FS).
RVP was measured in the following four groups of patients and age- and sex-matched healthy controls: (a) 15 patients with a POAG and a FS (POAG/FS+); (b) 15 patients with a POAG but without a FS (POAG/FS-); (c) 14 healthy subjects with a FS (healthy/FS+) and (d) 16 healthy subjects without a FS (healthy/FS-). RVP was measured in all participants bilaterally by means of contact lens ophthalmodynamometry. Ophthalmodynamometry is done by applying increasing pressure on the eye via a contact lens. The minimum force required to induce a venous pulsation is called ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP].
The participants with a FS (whether patients with POAG or healthy subjects), had a significantly higher RVP compared to subjects without a FS (p = 0.0103). Patients with a POAG and FS (POAG/FS+) had a significantly higher RVP compared to patients without a FS (POAG/FS-) (p = 0.0301). There was a notable trend for a higher RVP in the healthy/FS + group compared to the healthy/FS - group, which did not reach statistical significance (p = 0.0898).
RVP is higher in subjects with a FS, particularly in glaucoma patients. The causal relationship needs to be further evaluated.
Cotton fiber, a highly elongated, thickened single cell of the seed epidermis, is a powerful cell wall research model. Fiber length, largely determined during the elongation stage, is a key property of fiber quality. Several studies using expressed sequence tags and microarray analysis have identified transcripts that accumulate preferentially during fiber elongation. To further show the mechanism of fiber elongation, we used Digital Gene Expression Tag Profiling to compare transcriptome data from longer fiber chromosome introgressed lines (CSILs) containing segments of various Gossypium barbadense chromosomes with data from its recurrent parent TM-1 during fiber elongation (from 5 DPA to 20 DPA).
A large number of differentially expressed genes (DEGs) involved in carbohydrate, fatty acid and secondary metabolism, particularly cell wall biosynthesis, were highly upregulated during the fiber elongation stage, as determined by functional enrichment and pathway analysis. Furthermore, DEGs related to hormone responses and transcription factors showed upregulated expression levels in the CSILs. Moreover, metabolic and regulatory network analysis indicated that the same pathways were differentially altered, and distinct pathways exhibited altered gene expression, in the CSILs. Interestingly, mining of upregulated DEGs in the introgressed segments of these CSILs based on D-genome sequence data showed that these lines were enriched in glucuronosyltransferase, inositol-1, 4, 5-trisphosphate 3-kinase and desulfoglucosinolate sulfotransferase activity. These results were similar to the results of transcriptome analysis.
This report provides an integrative network about the molecular mechanisms controlling fiber length, which are mainly tied to carbohydrate metabolism, cell wall biosynthesis, fatty acid metabolism, secondary metabolism, hormone responses and Transcription factors. The results of this study provide new insights into the critical factors associated with cell elongation and will facilitate further research aimed at understanding the mechanisms underlying cotton fiber elongation.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-838) contains supplementary material, which is available to authorized users.
CSIL; DEG; Fiber length; Functional enrichment; Metabolic pathway analysis; Transcriptome
Infiltrating macrophages are a key component of inflammation during tumorigenesis, but the direct evidence of such linkage remains unclear. We report here that persistent co-culturing of immortalized prostate epithelial cells with macrophages, without adding any carcinogens, induces prostate tumorigenesis, and that induction involves the alteration of signaling of macrophage androgen receptor (AR)-inflammatory chemokine CCL4-STAT3 activation as well as epithelial-to-mesenchymal transition (EMT) and down-regulation of p53/PTEN tumor suppressors. In vivo studies further showed that PTEN+/− mice lacking macrophage AR developed far fewer prostatic intraepithelial neoplasia (PIN) lesions, supporting an in vivo role for macrophage AR during prostate tumorigenesis. CCL4 neutralizing antibody effectively blocked macrophage-induced prostate tumorigenic signaling, and targeting AR via an AR degradation enhancer, ASC-J9®, reduced CCL4 expression and xenografted tumor growth in vivo. Importantly, CCL4 upregulation was associated with increased Snail expression and down-regulation of p53/PTEN in high-grade PIN and prostate cancer. Together, our results identify the AR-CCL4-STAT3 axis as key regulators during prostate tumor initiation and highlight the important roles of infiltrating macrophages and inflammatory cytokines for the prostate tumorigenesis.
androgen receptor; CCL4; macrophages; epithelial-to-mesenchymal transition; prostate cancer
Chromatin is subject to proofreading and repair mechanisms during the process of DNA replication, as well as repair to maintain genetic and epigenetic information and genome stability. The dynamic structure of chromatin modulates various nuclear processes, including transcription and replication, by altering the accessibility of the DNA to regulatory factors. Structural changes in chromatin are affected by the chemical modification of histone proteins and DNA, remodeling of nucleosomes, incorporation of variant histones, noncoding RNAs, and nonhistone DNA-binding proteins. Phenotypic diversity and fidelity can be balanced by controlling stochastic switching of chromatin structure and dynamics in response to the environmental disruptors and endogenous stresses. The dynamic chromatin remodeling can, therefore, serve as a sensor, through which environmental and/or metabolic agents can alter gene expression, leading to global cellular changes involving multiple interactive networks. Furthermore its recent evidence also suggests that the epigenetic changes are heritable during the development. This review will discuss the environmental sensing system for chromatin regulation and genetic and epigenetic controls from developmental perspectives.
Chromatin assembly; Chromatin regulation; Endocrine-disrupting chemicals; Environmental stress; Epigenesis; Epigenetic inheritance
Activation of EGFR signaling pathway leads to prostate cancer bone metastasis; however, therapies targeting EGFR have demonstrated limited effectiveness and led to drug resistance. miR-203 levels are down-regulated in clinical samples of primary prostate cancer and further reduced in metastatic prostate cancer. Here we show that ectopic miR-203 expression displayed reduced bone metastasis and induced sensitivity to tyrosine kinase inhibitors (TKIs) treatment in a xenograft model. Our results demonstrate that the induction of bone metastasis and TKI resistance require miR-203 down-regulation, activation of the EGFR pathway via altered expression of EGFR ligands (EREG and TGFA) and anti-apoptotic proteins (API5, BIRC2, and TRIAP1). Importantly, a sufficient reconstitution of invasiveness and resistance to TKIs treatment was observed in cells transfected with anti-miR-203. In prostate cancer patients, our data showed that miR-203 levels were inversely correlated with the expression of two EGFR ligands, EREG and TGFA, and an EGFR dependent gene signature. Our results support the existence of a miR-203, EGFR, TKIs resistance regulatory network in prostate cancer progression. We propose that the loss of miR-203 is a molecular link in the progression of prostate cancer metastasis and TKIs resistance characterized by high EGFR ligands output and anti-apoptotic proteins activation.
Bone metastasis/Epidermal growth factor receptor (EGFR)/Prostate cancer/miR-203/KRAS/Tyrosine kinase inhibitors (TKIs) resistance
Inflammatory myofibroblastic tumor, also known as inflammatory pseudotumor, plasma cell granuloma or inflammatory myofibroblastoma, is characterized histopathologically by myofibroblastic spindle cells with inflammatory cell infiltrates composed of plasma cells, lymphocytes and eosinophils. Inflammatory myofibroblastic tumor is typically seen in children or young adults and is most commonly localized to the lungs, but it can occur anywhere in the body. To date, however, only a few cases involving the stomach have been reported. Herein, we present a case of gastric inflammatory myofibroblastic tumor in an adult woman with an initial symptom of high fever.
Inflammatory myofibroblastic tumor; stomach; inflammatory pseudotumor; high fever; surgery
Genkwanin is one of the major non-glycosylated flavonoids in many herbs with anti-inflammatory activities. Although its anti-inflammatory activity in vivo has been reported, the potential molecular mechanisms remain obscure. In this study, by pharmacological and genetic approaches, we explore the anti-inflammatory effects of genkwanin in LPS-activated RAW264.7 macrophages. Genkwanin potently decreases the proinflammatory mediators, such as iNOS, TNF-α, IL-1β and IL-6, at the transcriptional and translational levels without cytotoxicity, indicating the excellent anti-inflammatory potency of genkwanin in vitro. Mechanism study shows that genkwanin significantly suppresses the p38- and JNK-mediated AP-1 signaling pathway and increases the mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) expression at the posttranscriptional level. We also confirmed that microRNA-101 (miR-101) is a negative regulator of MKP-1 expression. Moreover, regardless of miR-101-deficient cells or miR-101-abundant cells, the suppression effects of genkwanin on supernatant proinflammatory mediators' levels are far less than that in respective negative control cells, suggesting that genkwanin exerts anti-inflammatory effect mainly through reducing miR-101 production. However, genkwanin can't affect the level of phospho-Akt (p-Akt), indicating that the phosphorylation of Akt may be not responsible for the effect of genkwanin on miR-101 production. We conclude that genkwanin exerts its anti-inflammatory effect mainly through the regulation of the miR-101/MKP-1/MAPK pathway.
To investigate the association of survivin −31G/C, −141G/C, and −241T/C polymorphisms with colorectal cancer (CRC) susceptibility and explore the mechanisms of the survivin polymorphism in CRC development. A case–control study was conducted of 275 CRC cases and 270 healthy controls. Polymorphisms of survivin −31G/C, −141G/C, and −241T/C were genotyped by polymerase chain reaction–restriction fragment length polymorphism. Survivin and Ki-67 expression was analyzed by immunohistochemistry by the Envision technique for the paraffin sections of 152 CRC. It showed that the −31G/C genotype and allele distribution were significantly different between the CRC cases and controls. The −31CC genotype and −31C allele were over-represented among the CRC cases. Compared with the CC genotype, the GC and GG genotypes had a significantly decreased risk of CRC (p=0.015). Survivin and Ki-67 expression of patients with the CC genotype was significantly higher than the patients with the GC and GG genotypes. In addition, a significantly positive correlation was found between expression of Survivin and Ki-67. There were no significant difference of the −141G/C and −241T/C polymorphism distributions among cases and controls. Survivin 31G/C may adjust the Survivin expression, and it might contribute to a risk of developing CRC.
Three polymorphisms of the survivin gene were examined in normal individuals and colorectal cancer patients. Tissues were studied for expression of survivin and Ki-67 expression by immunohistochemistry. 31G/C altered protein expression and may contribute to the risk of colorectal cancer.
Fiber strength is the key trait that determines fiber quality in cotton, and it is closely related to secondary cell wall synthesis. To understand the mechanism underlying fiber strength, we compared fiber transcriptomes from different G. barbadense chromosome introgression lines (CSILs) that had higher fiber strengths than their recipient, G. hirsutum acc. TM-1. A total of 18,288 differentially expressed genes (DEGs) were detected between CSIL-35431 and CSIL-31010, two CSILs with stronger fiber and TM-1 during secondary cell wall synthesis. Functional classification and enrichment analysis revealed that these DEGs were enriched for secondary cell wall biogenesis, glucuronoxylan biosynthesis, cellulose biosynthesis, sugar-mediated signaling pathways, and fatty acid biosynthesis. Pathway analysis showed that these DEGs participated in starch and sucrose metabolism (328 genes), glycolysis/gluconeogenesis (122 genes), phenylpropanoid biosynthesis (101 genes), and oxidative phosphorylation (87 genes), etc. Moreover, the expression of MYB- and NAC-type transcription factor genes were also dramatically different between the CSILs and TM-1. Being different to those of CSIL-31134, CSIL-35431 and CSIL-31010, there were many genes for fatty acid degradation and biosynthesis, and also for carbohydrate metabolism that were down-regulated in CSIL-35368. Metabolic pathway analysis in the CSILs showed that different pathways were changed, and some changes at the same developmental stage in some pathways. Our results extended our understanding that carbonhydrate metabolic pathway and secondary cell wall biosynthesis can affect the fiber strength and suggested more genes and/or pathways be related to complex fiber strength formation process.
It can be argued that an ideal anti-cocaine medication would be one that accelerates cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. hydrolysis catalyzed by butyrylcholinesterase (BChE) in plasma. However, wild-type BChE has a low catalytic efficiency against naturally occurring (−)cocaine. Interestingly, wild-type BChE has a much higher catalytic activity against unnatural (+)cocaine. According to available positron emission tomography (PET) imaging analysis using [11C](−)-cocaine and [11C](+)-cocaine tracers in human subjects, only [11C](−)-cocaine was observed in the brain, whereas no significant [11C](+)-cocaine signal was observed in the brain. The available PET data imply that an effective therapeutic enzyme for treatment of cocaine abuse could be an exogenous cocaine-metabolizing enzyme with a catalytic activity against (−)cocaine comparable to that of wild-type BChE against (+)-cocaine. Our recently designed A199S/F227A/S287G/A328W/Y332G mutant of human BChE has a considerably improved catalytic efficiency against (−)-cocaine and has been proven active in vivo. In the present study, we have characterized the catalytic activities of wild-type BChE and the A199S/F227A/S287G/A328W/Y332G mutant against both (+)- and (−)-cocaine at the same time under the same experimental conditions. Based on the obtained kinetic data, the A199S/F227A/S287G/A328W/Y332G mutant has a similarly high catalytic efficiency (kcat/KM) against (+)- and (−)-cocaine, and indeed has a catalytic efficiency (kcat/KM = 1.84×109 M−1 min−1) against (−)-cocaine comparable to that (kcat/KM = 1.37×109 M−1 min−1) of wild-type BChE against (+)-cocaine. Thus, the mutant may be used to effectively prevent (−)-cocaine from entering brain and producing physiological effects in the enzyme-based treatment of cocaine abuse.
Bacillus thuringiensis represents one of the six species of "Bacillus cereus group" in the genus Bacillus within the family Bacillaceae. Strain Sbt003 was isolated from soil and identified as B. thuringiensis. It harbors at least seven plasmids and produces three shapes of parasporal crystals including oval, bipyramidal and rice. SDS-PAGE analysis of spore-crystal suspension of this strain reveals six major protein bands, which implies the presence of multiple parasporal crystal genes. Bioassay of this strain reveals that it shows specific activity against nematodes and human cancer cells. In this study, we report the whole genomic shotgun sequences of Sbt003. The high-quality draft of the genome is 6,175,670 bp long (including chromosome and plasmids) with 6,372 protein-coding and 80 RNA genes.
The Next-Generation sequencing; parasporal crystal protein; Bacillus thuringiensis
Meningothelial cells (MECs) are the cellular components of the meninges. As such, they provide important barrier function for the central nervous system (CNS) building the interface between neuronal tissue and the cerebrospinal fluid (CSF), and are also part of the immune response of the CNS.
Human, immortalized MECs were analyzed by flow cytometry and confocal microscopy to study the uptake of apoptotic cells. Furthermore, cytokine and chemokine production by MECs was analyzed by cytokine array and ELISA.
We found that MECs are highly active phagocytes able of ingesting and digesting large amounts of apoptotic cells. Furthermore, the uptake of apoptotic cells by MECs was immune suppressive via inhibiting the secretion of pro-inflammatory and chemoattractant cytokines and chemokines IL-6, IL-8, IL-16, MIF, and CXCL1, while increasing the secretion of anti-inflammatory IL-1 receptor antagonist by MECs.
MECs respond with the secretion of anti-inflammatory cytokines and chemokines following the uptake of apoptotic cells potentially connecting these cells to processes important for the shut-down of immune responses in the brain.
Meningothelial cells; Apoptotic cells; Cytokines; Cerebrospinal fluid; Central nervous system; Optic nerve
molecular devices; molecular switches; polymers; self-assembly; template synthesis
Clinical investigations highlight the increased incidence of metabolic syndrome in prostate cancer (PCa) patients receiving androgen deprivation therapy (ADT). Studies using global androgen receptor (AR) knockout mice demonstrate that AR deficiency results in the development of insulin resistance in males. However, mechanisms by which AR in individual organs coordinately regulates insulin sensitivity remain unexplored. Here we tested the hypothesis that functional AR in the brain contributes to whole-body insulin sensitivity regulation and to the metabolic abnormalities developed in AR-deficient male mice. The mouse model selectively lacking AR in the central nervous system and AR-expressing GT1-7 neuronal cells were established and used to delineate molecular mechanisms in insulin signaling modulated by AR. Neuronal AR deficiency leads to reduced insulin sensitivity in middle-aged mice. Neuronal AR regulates hypothalamic insulin signaling by repressing nuclear factor-κB (NF-κB)–mediated induction of protein-tyrosine phosphatase 1B (PTP1B). Hypothalamic insulin resistance leads to hepatic insulin resistance, lipid accumulation, and visceral obesity. The functional deficiency of AR in the hypothalamus leads to male mice being more susceptible to the effects of high-fat diet consumption on PTP1B expression and NF-κB activation. These findings suggest that in men with PCa undergoing ADT, reduction of AR function in the brain may contribute to insulin resistance and visceral obesity. Pharmacotherapies targeting neuronal AR and NF-κB may be developed to combat the metabolic syndrome in men receiving ADT and in elderly men with age-associated hypogonadism.
Neutral lipid storage is enhanced by nitrogen deprivation (ND) in numbers of green microalgal species. However, little is known about the metabolic pathways whose transcription levels are most significantly altered following ND in green microalgae, especially the nonmodel species.
To start gaining knowledge on this, we performed transcriptome profiling of the nonmodel green microalga Botryosphaerella sudeticus cells in response to ND. Transcriptome of B. sudeticus is de novo assembled based on millions of HiSEQ short sequence reads using CLC Genomics Workbench software. The resulting non-redundant ESTs are annotated based on the best hits generated from the BLASTX homology comparison against the “best” proteins in the model microalgae Chlamydomonas reinhardtii and Chlorella variabilis. By using a pathway-based approach according to KEGG databases, we show that ESTs encoding ribosomal proteins and photosynthetic functions are the most abundantly expressed ESTs in the rapidly growing B. sudeticus cells. We find that ESTs encoding photosynthetic function but not the ribosomal proteins are most drastically downregulated upon ND. Notably, ESTs encoding lipid metabolic pathways are not significantly upregulated. Further analyses indicate that chlorophyll content is markedly decreased by 3-fold and total lipid content is only slightly increased by 50%, consistent with the transcriptional profiling. On the other hand, carbon content and photosynthesis efficiency are only marginally decreased by 7% and 20%, respectively, indicating that photosynthesis is only slightly reduced upon drastic downregulation of photosynthetic ESTs and chlorophyll content upon ND. In addition, TAG content is found to be greatly increased by 50-fold, though total lipid content is only slightly increased by 1.5-fold.
Taken together, our results suggest that light-harvesting proteins and chlorophylls are in excess in B. sudeticus. Degradation of excess photosynthesis proteins is most likely a mechanism for recycling of nitrogen-rich molecules to synthesize new proteins for preparation of gametogenesis and zygospore formation in adaptation and survival upon ND. Furthermore, our analyses indicate that TAG accumulation is largely attributed to the modification of other pre-existing lipid molecules, rather than de novo synthesis. We propose that this is likely an evolutionarily conserved mechanism in many green microalgae species.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-14-715) contains supplementary material, which is available to authorized users.
Next-generation sequencing; De novo assembly; Transcriptome profiling; Metabolic pathways; B. sudeticus UTEX2629
Increased CCL2 expression in prostate cancer (PCa) cells enhanced metastasis via macrophage recruitment. However, its linkage to androgen receptor (AR)-mediated PCa progression remains unclear. Here, we identified a previously unrecognized regulation: targeting AR with siRNA in PCa cells increased macrophage recruitment via CCL2 up-regulation, which might then result in enhancing PCa invasiveness. Molecular mechanism dissection revealed that targeting PCa AR with siRNA promoted PCa cell migration/invasion via CCL2-dependent STAT3 activation and epithelial–mesenchymal transition (EMT) pathways. Importantly, pharmacologic interruption of the CCL2/CCR2-STAT3 axis suppressed EMT and PCa cell migration, providing a new mechanism linking CCL2 and EMT. Simultaneously targeting PCa AR with siRNA and the CCL2/CCR2-STAT3 axis resulted in better suppression of PCa growth and metastasis in a xenograft PCa mouse model. Human PCa tissue microarray analysis suggests that increased CCL2 expression may be potentially associated with poor prognosis of PCa patients. Together, these results may provide a novel therapeutic approach to better battle PCa progression and metastasis at the castration resistant stage via the combination of targeting AR with siRNA and anti-CCL2/CCR2-STAT3 signalling.
androgen receptor; CCL2; epithelial–mesenchymal transition; prostate cancer; STAT3
Rituximab, a monoclonal antibody against CD20+ antigen specific B cell, has been increasingly used in the treatment of non-Hodgkin’s lymphoma and some other autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. It is noted that Rituximab could enhanced the efficacy of CHOP-based chemotherapy. Meanwhile it could increase the opportunity of lung infection. Pneumocystis jiroveci pneumonia (PCP), a rare opportunistic infection that was not reported in the large-scale clinical trials of Rituximab, was found recently in patients with non-Hodgkin’s lymphoma treated with remedy containing Rituximab. We herein report two cases of PCP in lymphoma patients after Rituximab-containing chemotherapy. Both patients were successfully treated, with trimethoprim-sulfamethoxazole (TMP-SMX) in one case and Caspofungin alone in the other. We also reviewed the literature and concluded that PCP is an infrequent but potentially life-threatening infection in patients with non-Hodgkin’s lymphoma subjected to Rituximab-containing regimen. Therefore, adequate prophylaxis, timely diagnosis and treatment are necessary.
Rituximab; non-Hodgkin’s lymphoma; pneumocystis jiroveci pneumonia (PCP); Caspofungin
Adult Hirschsprung’s disease (HD) is a rare motor disorder of the gut that is frequently misdiagnosed as refractory constipation. The primary pathogenic defect in adult HD is identical to that seen in infancy or childhood, and is characterized by the total absence of intramural ganglion cells of the submucosal (Meissner) and myenteric (Auerbach) neural plexuses in the affected segment of the bowel. Ninety-four percent of HD cases are diagnosed before the patient reaches 5 years of age, however, on rare occasion, mild cases of HD may go undiagnosed until he or she reaches adulthood. In this study, we describe four cases of adult HD with a history of longstanding recurrent constipation, relieved by laxatives, and presenting to the Department of Gastrointestinal Surgery with progressive abdominal distention, colicky pain or acute intestinal obstruction. Barium enema or computed tomography revealed a grossly distended proximal large colon with fecal retention. Intraoperative frozen section biopsy was performed in all cases and showed aganglionosis of the stenotic segment and a normal distal rectum. In all cases, patient symptoms were completely resolved and there were no complications arising immediately post-surgery or at one-year follow-up. Adult HD should be considered in the differential diagnosis of cases where adult patients present with chronic constipation or even acute intestinal obstruction. The modified one-stage Martin-Duhamel or Rehbein’s procedure is a feasible surgical option for treating cases of adult HD involving a segment or the entire bowel.
Adult; constipation; treatment; Hirschsprung’s disease
Vif forms a complex with Elongin B/C, Cullin-5 and Rbx-1 to induce the polyubiquitination and proteasome-mediated degradation of human APOBEC3G (hA3G). These interactions serve as potential targets for anti-HIV-1 drug development. We have developed a cell culture-based assay to measure Vif-induced A3G degradation. The assay is based on α-complementation, the ability of β-galactosidase fragments to complement in trans. A3G expressed with a fused α-peptide was enzymatically active, complemented a coexpressed ω fragment and could be targeted for degradation by Vif. Vif reduced β-galactosidase activity in the cell by 10-30-fold. The assay was validated by testing various A3G and Vif point mutants. The assay accurately detected the effects of D128 in A3G, and the BC box, Cul5 box, and HCCH motifs of Vif. The results showed a strict association of Vif biological function with hA3G degradation. These findings support hA3G degradation as a requirement for Vif function. The Vif α-complementation assay may be a useful tool for the identification of Vif inhibitors.
HIV-1; Vif; APOBEC3G; α-complementation; cell-based assay; protein degradation; high throughput screening