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
To investigate the surgical outcome of a universal pedicle screw-V rod system and isthmic bone grafting for isthmic spondylolysis.
Twenty-four patients with isthmic spondylolysis at L5 and grade 0–I spondylolisthesis (Meyerding classification) received isthmic bone graft and stabilization using the universal pedicle screw-V rod system. Back pain was evaluated using the visual analog scale (VAS) and time to bone healing, improvement in spondylolisthesis and intervertebral space height at L5/S1 and L4/L5 were assessed.
Twenty-one patients were followed up for 24 months and included in the analysis. Back pain was markedly improved at 3 months postoperatively with a statistical difference in VAS scores compared with preoperative VAS scores (P<0.001). The VAS scores were 0 to 3 at 6 months postoperatively in all patients and no back pain was reported in all patients except 2 patients who complained of back pain after prolonged sitting. X-ray examination showed a bone graft healing time of 3 to 12 months. Grade I spondylolisthesis improved to grade 0 in 4 patients and no noticeable change was observed in the remaining 17 cases. The intervertebral space height at L5/S1 was statistically increased (P<0.05) while no statistically significant change was seen at L4/L5. There was no statistically significant difference in the ROM of the intervertebral disks of L5/S1 and L4/5 before and after surgery.
The universal pedicle screw-V rod system and isthmic bone grafting directly repairs isthmic spondylolysis and reduces back pain, prevents anterior displacement of the diseased segment and maintains intervertebral space height, thus offering a promising alternative to current approaches for isthmic spondylolysis.
The catalytic mechanism for butyrylcholineserase (BChE)-catalyzed hydrolysis of acetylthiocholine (ATCh) has been studied by performing pseudobond first-principles quantum mechanical/molecular mechanical-free energy (QM/MM-FE) calculations on both acylation and deacylation of BChE. Additional quantum mechanical (QM) calculations have been carried out, along with the QM/MM-FE calculations, to understand the known substrate activation effect on the enzymatic hydrolysis of ATCh. It has been shown that the acylation of BChE with ATCh consists of two reaction steps including the nucleophilic attack on the carbonyl carbon of ATCh and the dissociation of thiocholine ester. The deacylation stage includes nucleophilic attack of a water molecule on the carboxyl carbon of substrate and dissociation between the carboxyl carbon of substrate and hydroxyl oxygen of Ser198 side chain. QM/MM-FE calculation results reveal that the acylation of BChE is rate-determining. It has also been demonstrated that an additional substrate molecule binding to the peripheral anionic site (PAS) of BChE is responsible for the substrate activation effect. In the presence of this additional substrate molecule at PAS, the calculated free energy barrier for the acylation stage (rate-determining step) is decreased by ~1.7 kcal/mol. All of our computational predictions are consistent with available experimental kinetic data. The overall free energy barriers calculated for BChE-catalyzed hydrolysis of ATCh at regular hydrolysis phase and substrate activation phase are ~13.6 and ~11.9 kcal/mol, respectively, which are in reasonable agreement with the corresponding experimentally-derived activation free energies of 14.0 kcal/mol (for regular hydrolysis phase) and 13.5 kcal/mol (for substrate activation phase). .
Neuronal cell death is accompanied by mitochondrial dysfunction with mitochondrial maintenance critical to neuronal survival. The mitochondrial ubiquitin ligase MARCH5 has dual roles in the upkeep of mitochondrial function. MARCH5 is involved in targeted degradation of proteins harmful to mitochondria and impacts mitochondrial morphology upstream of the fission protein Drp1. In a neuronal cell model, dominant-negative MARCH5 prevents mitochondrial fragmentation during neurodegenerative stress induced by the neuron-specific reactive oxygen generator 6-hydroxydopamine, the complex I inhibitor rotenone or Alzheimer’s-related amyloid beta peptide. In addition, preservation of mitochondrial function in terms of membrane potential and lower reactive oxygen generation was observed following inactivation of MARCH5. Our findings connect MARCH5 to neuronal stress responses and further emphasize the link between mitochondrial dynamics and function.
MARCH5; mitochondria; Aβ; neurodegeneration; mitochondrial quality control
To study the impact of the mitochondrial ubiquitin ligase MARCH5 on mitochondrial morphology and induction of apoptosis using an in vitro model of neuronal precursor cells exposed to glaucoma-relevant stress conditions.
RGC5 cells transfected with expression constructs for MARCH5, MARCH5H43W, Dpr1K38A or vector control were exposed to either elevated pressure of 30 mmHg, oxidative stress caused by mitochondrial electron transport chain (ETC) inhibition, or hypoxia-reoxygenation conditions. Mitochondrial morphology of RGC5 cells was analyzed following staining of the mitochondrial marker cytochrome c and photoactivatable GFP (PAGFP) diffusion assay. Induction of apoptotic cell death in these cells was determined by analyzing the release of cytochrome c from mitochondria into the cytosol and flow cytometry.
Exposure of RGC5 cells to oxidative stress conditions as well as to elevated pressure resulted in the fragmentation of the mitochondrial network in control cells as well as in cells expressing MARCH5. In cells expressing inactive MARCH5H43W or inactive DrpK38A, mitochondrial fragmentation was significantly blocked and mitochondrial morphology was comparable to that of control cells under normal conditions. Exposure of RGC5 cells to elevated pressure or oxidative stress conditions induced apoptotic cell death as assessed by cytochrome c release and DNA staining, while expression of dominant-negative MARCH5H43W or Drp1K38A did significantly delay cell death.
Preventing mitochondrial fragmentation through interference with the mitochondrial fission machinery protects neuronal cells from programmed cell death following exposure to stressors physiologically relevant to the pathogenesis of glaucoma.
Epithelial-mesenchymal transition (EMT) is implicated in various pathological processes within the prostate, including benign prostate hyperplasia (BPH) and prostate cancer progression. However, an ordered sequence of signaling events initiating carcinoma-associated EMT has not been established. In a model of transforming growth factor β (TGFβ)-induced prostatic EMT, SLUG is the dominant regulator of EMT initiation in vitro and in vivo, as demonstrated by the inhibition of EMT following Slug depletion. In contrast, SNAIL depletion was significantly less rate limiting. TGFβ-stimulated KLF4 degradation is required for SLUG induction. Expression of a degradation-resistant KLF4 mutant inhibited EMT, and furthermore, depletion of Klf4 was sufficient to initiate SLUG-dependent EMT. We show that KLF4 and another epithelial determinant, FOXA1, are direct transcriptional inhibitors of SLUG expression in mouse and human prostate cancer cells. Furthermore, self-reinforcing regulatory loops for SLUG-KLF4 and SLUG-FOXA1 lead to SLUG-dependent binding of polycomb repressive complexes to the Klf4 and Foxa1 promoters, silencing transcription and consolidating mesenchymal commitment. Analysis of tissue arrays demonstrated decreased KLF4 and increased SLUG expression in advanced-stage primary prostate cancer, substantiating the involvement of the EMT signaling events described in model systems.
Genomic rearrangements commonly occur in many types of cancers and often initiate or alter the progression of disease. Here we describe an in vivo mouse model that recapitulates the most frequent rearrangement in prostate cancer, the fusion of the promoter region of TMPRSS2 with the coding region of the transcription factor, ERG. A recombinant bacterial artificial chromosome including an extended TMPRSS2 promoter driving genomic ERG was constructed and used for transgenesis in mice. TMPRSS2-ERG expression was evaluated in tissue sections and FACS-fractionated prostate cell populations. In addition to the anticipated expression in luminal cells, TMPRSS2-ERG was similarly expressed in the Sca-1hi/EpCAM+ basal/progenitor fraction, where expanded numbers of clonogenic self-renewing progenitors were found, as assayed by in vitro sphere formation. These clonogenic cells increased intrinsic self renewal in subsequent generations. In addition, ERG dependent self-renewal and invasion in vitro was demonstrated in prostate cell lines derived from the model. Clinical studies have suggested that the TMPRSS2-ERG translocation occurs early in prostate cancer development. In the model described here, the presence of the TMPRSS2-ERG fusion alone was not transforming but synergized with heterozygous Pten deletion to promote PIN. Taken together, these data suggest that one function of TMPRSS2-ERG is the expansion of self-renewing cells, which may serve as targets for subsequent mutations. Primary prostate epithelial cells demonstrated increased post transcriptional turnover of ERG compared to the TMPRSS2-ERG positive VCaP cell line, originally isolated from a prostate cancer metastasis. Finally, we determined that TMPRSS2-ERG expression occurred in both castration-sensitive and resistant prostate epithelial subpopulations, suggesting the existence of androgen-independent mechanisms of TMPRSS2 expression in prostate epithelium.
Butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) are highly homologous proteins with distinct substrate preferences. In this study we compared the active sites of monomers and tetramers of human BChE and human AChE after performing molecular dynamics (MD) simulations in water-solvated systems. By comparing the conformational dynamics of gating residues of AChE and BChE, we found that the gating mechanisms of the main door of AChE and BChE are responsible for their different substrate specificities. Our simulation of the tetramers of AChE and BChE indicates that both enzymes could have two dysfunctional active sites due to their restricted accessibility to substrates. The further study on catalytic mechanisms of multiple forms of AChE and BChE would benefit from our comparison of the active sites of the monomers and tetramers of both enzymes.
Rare earth elements (REEs) have been widely used to increase accumulation of biomass and secondary metabolites in medicinal plants in China. However, very few studies have investigated how REEs mediate secondary metabolism synthesis in medicinal plants. Lanthanum (La), an important REE, is known to improve the accumulation of secondary metabolites in medicinal plants and is widely distributed in China. However, few studies have evaluated the signal transduction leading to La-induced secondary metabolism in medicinal plants. In this study, LaCl3 treatment-induced multiple responses in Scutellaria baicalensis seedlings, including the rapid generation of jasmonic acid (JA), sequentially followed by the enhancement of baicalin production. Direct application of JA also promoted the synthesis of baicalin in the absence of LaCl3. LaCl3-induced baicalin synthesis was blocked by two different JA synthesis inhibitors. Our results showed that JA acts as a signal component within the signaling system leading to La-induced baicalin synthesis in S. baicalensis seedlings.
LaCl3; Jasmonic acid; Scutellaria baicalensis; Baicalin
The peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1) proteins are key regulators of cellular bioenergetics and are accordingly expressed in tissues with a high energetic demand. For example, PGC-1α and PGC-1β control organ function of brown adipose tissue, heart, brain, liver and skeletal muscle. Surprisingly, despite their prominent role in the control of mitochondrial biogenesis and oxidative metabolism, expression and function of the PGC-1 coactivators in the retina, an organ with one of the highest energy demands per tissue weight, are completely unknown. Moreover, the molecular mechanisms that coordinate energy production with repair processes in the damaged retina remain enigmatic. In the present study, we thus investigated the expression and function of the PGC-1 coactivators in the healthy and the damaged retina. We show that PGC-1α and PGC-1β are found at high levels in different structures of the mouse retina, most prominently in the photoreceptors. Furthermore, PGC-1α knockout mice suffer from a striking deterioration in retinal morphology and function upon detrimental light exposure. Gene expression studies revealed dysregulation of all major pathways involved in retinal damage and apoptosis, repair and renewal in the PGC-1α knockouts. The light-induced increase in apoptosis in vivo in the absence of PGC-1α was substantiated in vitro, where overexpression of PGC-1α evoked strong anti-apoptotic effects. Finally, we found that retinal levels of PGC-1 expression are reduced in different mouse models for retinitis pigmentosa. We demonstrate that PGC-1α is a central coordinator of energy production and, importantly, all of the major processes involved in retinal damage and subsequent repair. Together with the observed dysregulation of PGC-1α and PGC-1β in retinitis pigmentosa mouse models, these findings thus imply that PGC-1α might be an attractive target for therapeutic approaches aimed at retinal degeneration diseases.
Catalytic mechanism for butyrylcholineserase (BChE)-catalyzed hydrolysis of acetylcholine (ACh) has been studied by performing pseudobond first-principles quantum mechanical/molecular mechanical-free energy (QM/MM-FE) calculations on both acylation and deacylation of BChE. It has been shown that the acylation with ACh includes two reaction steps including the nucleophilic attack on the carbonyl carbon of ACh and the dissociation of choline ester. The deacylation stage includes nucleophilic attack of a water molecule on the carboxyl carbon of substrate and dissociation between the carboxyl carbon of substrate and hydroxyl oxygen of Ser198 side chain. Notably, despite of the fact that acetylcholinesterase (AChE) and BChE are very similar enzymes, the acylation of BChE with ACh is rate-determining, which is remarkably different from AChE-catalyzed hydrolysis of ACh in which the deacylation is rate-determining. The computational prediction is consistent with available experimental kinetic data. The overall free energy barrier calculated for BChE-catalyzed hydrolysis of ACh is 13.8 kcal/mol, which is in good agreement with experimentally-derived activation free energy of 13.3 kcal/mol.
This phase I study determined the maximum tolerated regimen and dose-limiting toxicities of pazopanib in combination with weekly paclitaxel, assessed the effect of pazopanib on the pharmacokinetic profile of paclitaxel, and evaluated antitumor activity.
To evaluate the maximum tolerated regimen (MTR), dose-limiting toxicities, and pharmacokinetics of pazopanib, an oral small-molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit, in combination with paclitaxel.
Patients and Methods.
Pazopanib was given daily with weekly paclitaxel on days 1, 8, and 15 every 28 days. Dose levels of pazopanib (mg/day)/paclitaxel (mg/m2) were 400/15, 800/15, 800/50, and 800/80. An expanded cohort was enrolled at the MTR. Plasma samples were collected to evaluate the effect of pazopanib, an inhibitor of cytochrome P450 (CYP)3A4, on the pharmacokinetics of paclitaxel, a CYP3A4 and CYP2C8 substrate.
Of 26 enrolled patients, 17 were treated at the MTR of 800 mg pazopanib and 80 mg/m2 paclitaxel. Dose-limiting toxicities included a grade 3 abscess and grade 2 hyperbilirubinemia. Other toxicities included elevated liver transaminases and diarrhea. Six patients (23%) had partial responses and 15 patients (58%) had stable disease. Administration of 800 mg pazopanib resulted in a 14% lower paclitaxel clearance and a 31% higher paclitaxel maximal concentration than with administration of paclitaxel alone at 15, 50, and 80 mg/m2. At the MTR, coadministration of 800 mg pazopanib and 80 mg/m2 paclitaxel resulted in a 26% higher geometric mean paclitaxel area under the curve.
Pazopanib, at a dose of 800 mg daily, can be safely combined with a therapeutic dose of paclitaxel at 80 mg/m2 when administered on days 1, 8, and 15, every 28 days. The observed greater plasma concentrations of paclitaxel given concurrently with pazopanib suggest that pazopanib is a weak inhibitor of CYP3A4 and CYP2C8.
Pazopanib; Paclitaxel; Vascular endothelial growth factor receptor tyrosine kinase inhibitor
Cocaine addiction and overdose are a well-known public health problem. There is no approved medication available for cocaine abuse treatment. Our recently designed and discovered high-activity mutant (A199S/S287G/A328W/Y332G) of human butyrylcholinesterase (BChE) has been recognized to be worth exploring for clinical application in humans as a potential anti-cocaine medication. The catalytic rate constant (kcat) and Michaelis-Menten constant (KM) for (-)-cocaine hydrolysis catalyzed by A199S/S287G/A328W/Y332G BChE (without fusion with any other peptide) have been determined to be 3,060 min-1 and 3.1 μM, respectively, in the present study. The determined kinetic parameters reveal that the un-fused A199S/S287G/A328W/Y332G mutant has a ∼1,080-fold improved catalytic efficiency (kcat/KM) against (-)-cocaine compared to the wild-type BChE. The ∼1,080-fold improvement in the catalytic efficiency of the un-fused A199S/S287G/A328W/Y332G mutant is very close to the previously reported the ∼1,000-fold improvement in the catalytic efficiency of the A199S/S287G/A328W/Y332G mutant fused with human serum albumin. These results suggest that the albumin fusion did not significantly change the catalytic efficiency of the BChE mutant while extending the plasma half-life. In addition, we have also examined the catalytic activities of the A199S/S287G/A328W/Y332G mutant against two other substrates, acetylthiocholine (ATC) and butyrylthiocholine (BTC). It has been shown that the A199S/S287G/A328W/Y332G mutations actually decreased the catalytic efficiencies of BChE against ATC and BTC, while considerably improving the catalytic efficiency of BChE against (-)-cocaine.
Enzyme therapy; hydrolase; drug overdose; cocaine addiction
We recently reported that the progestagen-associated endometrial protein (PAEP) gene is overexpressed and promotes tumor proliferation and metastasis in human melanoma.
To identify the molecules that regulate its expression and oncogenic properties, we analyzed the gene microarray profiling of melanoma samples of serial clinical stage.
We found that the expression profile of the PAEP gene parallels that of microphthalmia-associated transcription factor (MITF, r = 0.86), a master regulator of melanocyte development and melanoma progression. This parallelism was further confirmed with semiquantitative reverse transcriptase polymerase chain reaction analysis of melanoma-derived daughter cells. Transfection of melanoma cells with MITF small interfering RNA (siRNA) specifically diminishes PAEP gene expression, whereas PAEP siRNA transfection has no effect on MITF. Furthermore, knockdown of either the MITF or PAEP gene reveals a significant inhibition of tumor cell migration.
Our data indicate that PAEP expression is regulated in part by MITF and may thus play a role in MITF-mediated cell migration in human melanoma.
Cell migration; gene regulation; melanoma; microphthalmia-associated transcription factor; progestagen-associated endometrial protein
A unified computational approach based on free energy perturbation (FEP) simulations of transition states has been employed to calculate the mutation-caused shifts of the free energy change from the free enzyme to the rate-determining transition state for (−)-cocaine hydrolysis catalyzed by the currently most promising series of mutants of human butyrylcholinesterase (BChE) that contain the A199S/A328W/Y332G mutations. The FEP simulations were followed by Michaelis-Menten kinetics analysis determining the individual kcat and KM values missing for the A199S/F227A/A328W/Y332G mutant in this series. The calculated mutation-caused shifts of the free energy change from the free enzyme to the rate-determining transition state are in good agreement with the experimental kinetic data, demonstrating that the unified computational approach based on the FEP simulations of the transition states may be valuable for future computational design of new BChE mutants with a further improved catalytic efficiency against (−)-cocaine.
Butyrylcholinesterase; cocaine; transition state simulation; free energy perturbation; enzyme mutant design
The title compound, C16H16N2O·0.5H2O, is a substituted 1-phenylbenzimidazole, which belongs to the class of ATP-site inhibitors of the platelet-derived growth-factor receptor. In the crystal, the components are linked by an O—H⋯N hydrogen bond.
To study the dynamic character of aberration between the cornea and the ocular with aging, and to evaluate the symmetry of the aberrations between right and left eye in order to supply the data for clinic to do the refractive surgery reasonably.
This is a comparative case series study. 82 normal cases (164 eyes) including 37 females (74 eyes) and 45 males (90 eyes) were recruited through the routine examinations, Topolyzer and wavefront analysis. The average age was 25.9±5.0 years old (range 18 to 49 years old), and the mean spherical equivalent (SE) is -3.82±2.21D (range -1.00 to -6.00D). The changes of aberrations regarding age, the relationship between anterior corneal and total aberrations were analyzed, as well as the symmetry between right and left eyes by using Zernike terms.
The Z31, RMS3 of corneal aberrations, Z31, Z40 , RMS3 and RMS4 of ocular aberrations had a positive correlation with age. The zernike terms both in corneal and whole eye were significantly correlated between right and left eyes.
The corneal horizontal coma, ocular horizontal coma and ocular spherical aberrations become to increase at the age of more than 40 years old. The dynamic change of aberration with aging, balance between corneal and ocular, and the symmetric character between left eye and right eye should be designed carefully in the treatment nomogram before the refractive surgery.
cornea; ocular; aberration; age; change; character
The conserved SNF1/AMPK/SnRK1 complexes are global regulators of metabolic responses in eukaryotes and play a key role in the control of energy balance. Although α-type subunits of the SnRK1 complex have been characterized in several plant species, the biological function of β-type and γ-type subunits remains largely unknown. Here, we characterized AtPV42a and AtPV42b, the two homologous genes in Arabidopsis, which encode cystathionine-β-synthase (CBS) domain-containing proteins that belong to the PV42 class of γ-type subunits of the plant SnRK1 complexes.
Real-time polymerase chain reaction was performed to examine the expression of AtPV42a and AtPV42b in various tissues. Transgenic plants that expressed artificial microRNAs targeting these two genes were created. Reproductive organ development and fertilization in these plants were examined by various approaches, including histological analysis, scanning electron microscopy, transmission electron microscopy, and phenotypic analyses of reciprocal crosses between wild-type and transgenic plants. We found that AtPV42a and AtPV42b were expressed in various tissues during different developmental stages. Transgenic plants where AtPV42a and AtPV42b were simultaneously silenced developed shorter siliques and reduced seed sets. Such low fertility phenotype resulted from deregulation of late stamen development and impairment of pollen tube attraction conferred by the female gametophyte.
Our results demonstrate that AtPV42a and AtPV42b play redundant roles in regulating male gametogenesis and pollen tube guidance, indicating that the Arabidopsis SnRK1 complexes might be involved in the control of reproductive development.
In the racemic title compound, C15H19NO3S, the dihedral angle between the planes of the benzene ring and the O=S=O group is 56.92 (7)° and the cyclohexane ring adopts a chair conformation.
The molecule of the title compound, C22H26Si2, is centrosymmetric. The dihedral angle between the central benzene ring and its phenyl substituents is 67.7 (2)°. The crystal packing is stabilized by van der Waals forces.
The complete molecule of the title compound, C22H26Si2, is generated by a crystallographic centre of symmetry. The central benzene ring makes a dihedral angle of 26.7 (4)° with the 4-(dimethylsilyl)phenyl ring. There are weak C—H⋯π interactions in the crystal structure.
The COP9 signalosome (CSN) is a multiprotein complex that plays a critical role in diverse cellular and developmental processes in various eukaryotic organisms. Despite of its significance, current understanding of the biological functions and regulatory mechanisms of the CSN complex is still very limited. To unravel these molecular mechanisms, we have performed a comprehensive proteomic analysis of the human CSN complex using a new purification method and quantitative mass spectrometry. Purification of the human CSN complex from a stable 293 cell line expressing N-terminal HBTH-tagged CSN5 subunit was achieved by high-affinity streptavidin binding with TEV cleavage elution. Mass spectrometric analysis of the purified CSN complex has revealed the identity of its composition as well as N-terminal modification and phosphorylation of the CSN subunits. N-terminal modifications were determined for seven subunits, six of which have not been reported previously, and six novel phosphorylation sites were also identified. Additionally, we have applied the newly developed MAP-SILAC and PAM-SILAC methods to decipher the dynamics of the human CSN interacting proteins. A total of 52 putative human CSN interacting proteins were identified, most of which are reported for the first time. In comparison to PAM-SILAC results, 20 proteins were classified as stable interactors, whereas 20 proteins were identified as dynamic ones. This work presents the first comprehensive characterization of the human CSN complex by mass spectrometry-based proteomic approach, providing valuable information for further understanding of CSN complex structure and biological functions.
COP9 Signalosome; cullin-containing ubiquitin ligase; MAP-SILAC; PAM-SILAC; affinity purification; phosphorylation; quantitative mass spectrometry; dynamic interaction; CSN interacting proteins