Dimerization of SARS-CoV-2 nucleocapsid protein affects sensitivity of ELISA based diagnostics of COVID-19.

Nucleocapsid protein (N protein) is the primary antigen of the virus for development of sensitive diagnostic assays of COVID-19. In this paper, we demonstrate the significant impact of dimerization of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) N-protein on sensitivity of enzyme-linked immunosorbent assay (ELISA) based diagnostics. The expressed purified protein from E. coli is composed of dimeric and monomeric forms, which have been further characterized using biophysical and immunological techniques. Indirect ELISA indicated elevated susceptibility of the dimeric form of the nucleocapsid protein for identification of protein-specific monoclonal antibody as compared to the monomeric form. This finding also confirmed with the modelled structure of monomeric and dimeric nucleocapsid protein via HHPred software and its solvent accessible surface area, which indicates higher stability and antigenicity of the dimeric type as compared to the monomeric form. The sensitivity and specificity of the ELISA at 95% CI are 99.0% (94.5-99.9) and 95.0% (83.0-99.4), respectively, for the highest purified dimeric form of the N protein. As a result, using the highest purified dimeric form will improve the sensitivity of the current nucleocapsid-dependent ELISA for COVID-19 diagnosis, and manufacturers should monitor and maintain the monomer-dimer composition for accurate and robust diagnostics.

Expression and purification of recombinant SARS-CoV-2 nucleocapsid protein in inclusion bodies and its application in serological detection.

The current standard for the diagnosis of COVID-19 is the nucleic acid test of SARS-CoV-2 RNA, however, virus antibody detection has the advantages of convenient sample collection, high throughout, and low cost. When combining detection with nucleic acid detection, antibody detection can effectively compensate for nucleic acid detection. Virus infection always induce high antibody titer against SARS-CoV-2 nucleocapsid protein (N protein), which can be used to detect COVID-19 at both infected and convalescent patients. In this study we reported the expression and purification of N protein in E.coli from inclusion bodies by a combination of two cation exchange chromatography, and the yield of N protein was around 50 mg/L fermentation broth with more than 90% purity. A corresponding colloidal gold detection kit prepared with our purified N protein was used to verify the efficiency and accuracy our N protein in antibody detection method. Of the 58 COVID-19 PCR positive patients' inactivated serum samples, 40 samples were IgM positive (69.0%), and 42 samples were IgG positive (72.4%), and all 95 COVID-19 negative patients' inactivated serum samples were both IgM and IgG negative. Our results indicates that the refolded soluble N protein could be used for the preliminary detection of IgG and IgM antibodies against SARS-CoV- 2.

Circ_0020093 ameliorates IL-1ß-induced apoptosis and extracellular matrix degradation of human chondrocytes by upregulating SPRY1 via targeting miR-23b.

Osteoarthritis (OA) is a chronic disease characterized by articular cartilage degeneration and uncontrolled chondrocyte apoptosis. At present, accumulating evidence introduces that circular RNA (circRNA) is involved in the development of OA. The aim of our study was to explore the role and the functional mechanism of circ_0020093 in OA cell model. Human chondrocytes were treated with interleukin-1 beta (IL-1ß) to construct OA model. The expression of circ_0020093, miR-23b, and Sprouty 1 (SPRY1) mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell apoptosis was assessed by flow cytometry assay. The expression of extracellular matrix (ECM)-associated markers and SPRY1 protein level was detected by qRT-PCR and Western blot. Bioinformatics analysis-predicted relationship between miR-23b and circ_0020093 or SPRY1 was further verified by dual-luciferase reporter assay and RNA pull-down assay. In this study, we found that the expression of circ_0020093 and SPRY1 was declined, while miR-23b expression was elevated in IL-1ß-treated chondrocytes. IL-1ß induced chondrocyte apoptosis and ECM degradation, while these negative effects were alleviated by circ_0020093 overexpression or miR-23b inhibition. MiR-23b was a target of circ_0020093, and SPRY1 was a downstream target of miR-23b. Rescue experiments showed that miR-23b enrichment reversed the role of circ_0020093 overexpression, and SPRY1 knockdown also reversed the effects of miR-23b inhibition. Importantly, circ_0020093 positively regulated SPRY1 expression by targeting miR-23b. In conclusion, circ_0020093 ameliorates IL-1ß-induced apoptosis and ECM degradation of human chondrocytes by regulating the miR-23b/SPRY1 axis.

Mechanism of ARPP21 antagonistic intron miR-128 on neurological function repair after stroke.

OBJECTIVE: Stroke is a cerebrovascular disorder that often causes neurological function defects. ARPP21 is a conserved host gene of miR-128 controlling neurodevelopmental functions. This study investigated the mechanism of ARPP21 antagonistic intron miR-128 on neurological function repair after stroke. METHODS: Expressions of ARPP21 and miR-128 in stroke patients were detected. The mouse neurons and astrocytes were cultured in vitro and treated with oxygen-glucose deprivation (OGD). The OGD-treated cells were transfected with pc-ARPP21 and miR-128 mimic. The proliferation of astrocytes, and the apoptosis of neurons and astrocytes were detected, and inflammatory factors of astrocytes were measured. The binding relationship between miR-128 and CREB1 was verified. The rat model of middle cerebral artery occlusion (MCAO) was established. ARPP21 expression in model rats was detected. The effects of pc-ARPP21 on neuron injury, brain edema volume, and cerebral infarct in rats were observed. RESULTS: ARPP21 expression was downregulated and miR-128 expression was upregulated in stroke patients. pc-ARPP21 facilitated the proliferation of astrocytes and inhibited apoptosis of neurons and astrocytes, and reduced inflammation of astrocytes. miR-128 mimic could reverse these effects of pc-ARPP21 on neurons and astrocytes. miR-128 targeted CREB1 and reduced BDNF secretion. In vitro experiments confirmed that ARPP21 expression was decreased in MCAO rats, and pc-ARPP21 promoted neurological function repair after stroke. CONCLUSION: ARPP21 upregulated CREB1 and BDNF expressions by antagonizing miR-128, thus inhibiting neuronal apoptosis and promoting neurological function repair after stroke. This study may offer a novel target for the management of stroke.

L-carnitine extenuates endocrine disruption, inflammatory burst and oxidative stress in carbendazim-challenged male rats via upregulation of testicular StAR and FABP9, and downregulation of P38-MAPK pathways.

We have addressed in the current study the potential of L-carnitine (LC) to extenuate the reproductive toxic insults of carbendazim (CBZ) in male rats, and the molecular mechanisms whereby carnitine would modify the spermatogenic and steroidogenic derangements invoked by the endocrine disruptor. Herein, animals received daily doses of carbendazim (100 mg/kg) by gavage for 8 weeks. Another CBZ-challenged group was co-supplemented with LC (500 mg/kg, IP) twice weekly for 8 weeks. Sperm quantity and quality (morphology, motility and viability), serum testosterone and gonadotropins, and thyroid hormone levels were assessed. Serum tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations were determined by ELISA. Oxidant/antioxidant status in rat testis was investigated via measuring testicular contents of malondialdehyde (MDA) and reduced glutathione (GSH), as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Immunohistochemical localizations of the junctional protein; occludin, and inflammatory markers; inducible nitric oxide synthase (iNOS) and nuclear factor kappa beta (NF-κB) were further analyzed. A host of transduction genes that regulate spermatogenic and steroidogenic pathways, and their encoded proteins namely, Steroidogenic Acute Regulatory Protein (StAR), Fatty acid binding protein 9 (FABP9) and P38-mitogen activated protein kinase (P38-MAPK) were assessed by real time quantitative (RT-qPCR) and Western blot. LC improved rat spermiogram, testicular histological alterations and endocrine perturbances, and modulated genes' expressions and their respective proteins. In conclusion, LC effects appear to reside for the most part on its endocrine-preserving, anti-oxidant and anti-inflammatory properties through a myriad of interlaced signal transductions that ultimately recapitulated its beneficial effects on spermatogenesis and steroidogenesis.

Nuclear expression of NHERF1/EBP50 in Clear Cell Renal Cell Carcinoma.

The Na/H exchange regulatory factor 1 or Ezrin-radixin-moesin-binding phosphoprotein 50 (NHERF1/EBP50) is an adaptor protein implicated in the stabilization of molecular complexes linking extracellular signals with the cytoskeleton machinery. NHERF1 expression at the cell cortex is associated with the maintenance of adherent junction integrity in polarized epithelia. The role of NHERF1 in cancer depends on its localization within the cell, acting, in most cases, as a tumor suppressor when localized at the cell membrane, and as an oncogene, when expressed in the cytoplasm or the nucleus of cancer cells. The distribution of NHERF1 in renal cell carcinoma (RCC) has not been yet investigated. In this study, NHERF1 expression was examined by immunohistochemistry in papillary and clear cell RCC. We observed membranous staining in papillary RCC, whereas NHERF1 expression was nuclear and membranous in clear cell RCC. In comparison, NHERF1 immunohistochemistry in clear cell carcinomas of the ovary showed mainly nuclear staining. Our finding of the specific NHERF1 nuclear expression in clear cell carcinomas may help to elucidate the molecular changes that regulate its nuclear accumulation and to better understand its role in this cell compartment.

Oocyte-secreted factors strongly stimulate sFRP4 expression in human cumulus cells.

Secreted frizzled-related protein-4 (SFRP4) belongs to a family of soluble ovarian-expressed proteins that participate in female reproduction, particularly in rodents. In humans, SFRP4 is highly expressed in cumulus cells (CCs). However, the mechanisms that stimulate SFRP4 in CCs have not been examined. We hypothesise that oocyte-secreted factors such as growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are involved in the regulation of SFRP4. Human CCs were collected from patients undergoing fertility treatments and treated with GDF9 or BMP15 or their combination in the presence of FSH or vehicle. FSH treatment significantly decreased SFRP4 mRNA levels when compared with nontreated cells. However, SFRP4 mRNA levels were increased significantly by GDF9 plus BMP15 in a concentration-dependent manner in the presence or absence of FSH. The combination of GDF9 plus BMP15 also increased SFRP4 protein levels and decreased the activity of the ß-catenin/T cell factor-responsive promoter significantly. GDF9 plus BMP15 inhibited steroidogenic acute regulatory protein and LH/hCG receptor stimulation by FSH, while treatment with SFRP4 blocked the stimulatory effect of FSH on these genes. The evidence demonstrates that GDF9 and BMP15 act in coordination to stimulate SFRP4 expression and suggests that SFRP4 mediates the anti-luteinising effects of the oocyte in human CCs.

Expression of transduced nucleolin promotes the clearance of accumulated α-synuclein in rodent cells and animal model.

Alpha-synuclein (αSyn) is a major component of Lewy bodies, which are a known pathogenic marker of Parkinson's disease (PD). The dysfunction of protein degradation machinery causes αSyn accumulation. The reinforcement of αSyn degradation is a potential therapeutic target for PD because accumulated αSyn is responsible for the pathogenesis of PD. Nucleolin (NCL) is essential in the formation of the nucleolar structure. The function of NCL is correlated with oxidative stress-mediated cell death. A previous study demonstrated that NCL overexpression alleviated rotenone-induced neurotoxic effects, whereas knockdown of NCL had the opposite effect. These results suggest that NCL malfunction would exacerbate PD pathology. Thus, it was hypothesized that the introduction of ectopic NCL could rescue α-synucleinopathy in PD. This study investigated whether the ectopic expression of NCL facilitates αSyn clearance. Ectopic expression of NCL was accomplished via the transfection of green fluorescent protein (GFP) or GFP-NCL in mouse embryonic fibroblasts (MEF) or transduction of GFP or GFP-NCL using lentivirus in rat primary cortical neurons and mouse substantia nigra. NCL overexpression enhanced the clearance of accumulated or aggregated αSyn in MEFs and rat primary cortical neurons. The activity of the autophagy-lysosome pathway was enhanced by NCL expression. NCL transduction in the substantia nigra, which was co-injected with αSyn fibrils, rescued PD manifestation. The elevation of NCL levels may reflect a therapeutic strategy for α-synucleinopathy in PD.

Deoxycholic Acid Upregulates Serum Golgi Protein 73 through Activating NF-κB Pathway and Destroying Golgi Structure in Liver Disease.

Golgi protein 73 (GP73) is upregulated in a variety of liver diseases, yet the detailed mechanism is poorly characterized. We analyzed GP73 in a retrospective cohort including 4211 patients with chronic liver disease (CLD) or hepatocellular carcinoma (HCC). The effect of deoxycholic acid (DCA) and nuclear factor-kappa B (NF-κB) on expression and release of GP73 in Huh-7 and SMMC7721 cells were studied. A mouse study was used to confirm our findings in vivo. A positive correlation was found between serum GP73 and total bile acid (TBA) in cirrhotic patients (r = 0.540, p < 0.001), higher than that in non-cirrhotic CLD (r = 0.318, p < 0.001) and HCC (r = 0.353, p < 0.001) patients. In Huh-7 and SMMC7721 cells, DCA upregulated the expression and release of GP73 in a dose- and time-dependent manner. After overexpressing NF-κB p65, the promoter activity, GP73 messenger RNA (mRNA) level, and supernatant GP73 level were increased. The promotion effect of DCA on GP73 release was attenuated after inhibiting the NF-κB pathway. Mutating the binding sites of NF-κB in the sequence of the GP73 promoter led to a declined promoting effect of DCA on GP73. The upregulation role of DCA in GP73 expression through the NF-κB pathway was confirmed in vivo. In addition, exposure to DCA caused disassembly of Golgi apparatus. In summary, DCA upregulates the expression and release of GP73 via activating the NF-κB pathway and destroying the Golgi structure.

Targeting nucleolin by RNA G-quadruplex-forming motif.

A high level of nucleolin (NCL) expression is often associated with a poor prognosis of patients with lung cancer (LC), suggesting that NCL can be used as a possible biomarker. NCL has been shown to display a marked preference for the binding to G-quadruplexes (G4). Here, we investigate the formation of an RNA quadruplex structure in a sequence found in the human precursor pre-MIR150 with the potential to recognize NCL. Circular dichroism (CD) spectra of pre-MIR150 G4-forming sequence (designated by rG4) indicate the formation of a parallel quadruplex structure in KCl or when complexed with the well-known G4 ligand PhenDC3. The thermal stability of rG4 is very high, and further increases in the presence of PhenDC3. The binding affinities of rG4 to PhenDC3 and NCL RBD1,2 are similar with KD values in the nanomolar range. PAGE results suggest the formation of a ternary quadruplex-ligand-protein complex (rG4-PhenDC3-NCL RBD1,2), indicative that PhenDC3 does not prevent the binding of rG4 to NCL RBD1,2. Finally, rG4 can recognize NCL-positive cells and, when fluorescently labeled, can be used as a probe for this protein. ELISA experiments indicate altered NCL expression patterns in liquid biopsies of LC patients in a non-invasive manner, potentially helping the diagnosis, prognosis, and patient response to treatment. Hence, labeled rG4 could be used as a detection probe of LC in liquid biopsies.

Plitidepsin has potent preclinical efficacy against SARS-CoV-2 by targeting the host protein eEF1A.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral proteins interact with the eukaryotic translation machinery, and inhibitors of translation have potent antiviral effects. We found that the drug plitidepsin (aplidin), which has limited clinical approval, possesses antiviral activity (90% inhibitory concentration = 0.88 nM) that is more potent than remdesivir against SARS-CoV-2 in vitro by a factor of 27.5, with limited toxicity in cell culture. Through the use of a drug-resistant mutant, we show that the antiviral activity of plitidepsin against SARS-CoV-2 is mediated through inhibition of the known target eEF1A (eukaryotic translation elongation factor 1A). We demonstrate the in vivo efficacy of plitidepsin treatment in two mouse models of SARS-CoV-2 infection with a reduction of viral replication in the lungs by two orders of magnitude using prophylactic treatment. Our results indicate that plitidepsin is a promising therapeutic candidate for COVID-19.

Shen-Fu Decoction could ameliorate intestinal permeability by regulating the intestinal expression of tight junction proteins and p-VASP in septic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Shen-Fu Decoction (SFD), a classic Traditional Chinese paired herb formulation, has been widely used for the treatment of sepsis in China. This study was carried out to assess the effects of SFD in sepsis-induced intestinal permeability and intestinal epithelial tight junction damage in rats with sepsis. MATERIALS AND METHODS: A rat model of sepsis was created by cecal ligation and puncture (CLP). Rats in Sham and CLP + vehicle groups received equal distilled water, while rats in SFD group were treated by gavage of SFD (3 mg/kg, twice a day) for 72h. Mortality, sepsis-induced peritoneal inflammation, intestinal and liver histopathology damage, intestinal permeability (serum FITC-dextran and D-lactate), serum LPS, serum inflammation (PCT, TNF-α, and IL-6), and liver function (AST and ALT) were evaluated. The levels of zonula occluden (ZO-1), Occludin, Claudin-1 were analyzed by Real-time quantitative PCR and Western blotting (WB) respectively. Vasodilator-stimulated phosphoprotein (VASP) and p-VASP in intestinal epithelium were analyzed by WB. RESULTS: Our study showed that SFD markedly reduced the mortality rate of CLP rats, prevented intestine and liver damage, relieved sepsis-induced intestinal permeability and inflammation elevation, ameliorated sepsis-induced impaired intestinal permeability by regulating the expression of ZO-1, Occludin, Claudin-1 and p-VASP. CONCLUSIONS: The herbal formula SFD may be useful for reducing sepsis-induced organic damage and mortality by ameliorating the condition of sepsis-induced intestinal permeability by regulating tight junction proteins and p-VASP.

Prognostic and therapeutic implications of NHERF1 expression and regulation in colorectal cancer.

BACKGROUND: Na+ /H+ exchanger regulatory factor 1 (NHERF1) has been implicated in the tumorigenesis of several cancer types and is a potential therapeutic target. The current study evaluated the relationship between NHERF1 expression and clinical outcome in colorectal cancer (CRC). METHODS: NHERF1 expression was evaluated by immunohistochemistry in 167 patients with CRC primary tumors, 37 patients with no disease, and 27 patients with metastatic CRC (mCRC); and in the orthotopically implanted tumors in mice. NHERF1 expression was manipulated in CRC cells using inducible short hairpin RNAs to determine its biological functions. RESULTS: High expression of NHERF1 correlated with CRC progression and metastasis, as well as significantly worse overall survival, recurrence-free survival, and disease-specific survival. Orthotopic implantation studies demonstrated increased NHERF1 expression in liver metastases. Treatment of CRC xenografts with insulin-like growth factor 1 receptor (IGF1R) inhibitors downregulated NHERF1 expression, indicating NHERF1 is downstream of IGF1R signaling. Knockdown of NHERF1 increased apoptosis and reduced X-linked inhibitor of apoptosis protein (XIAP) and survivin expression, indicating NHERF1 is critical for CRC cell survival. CONCLUSION: NHERF1 expression levels correlated with worse prognosis in patients with CRC and plays a critical role in CRC cell survival. Together, our findings establish NHERF1 as a novel potential marker for increased risk of CRC-specific mortality and identify NHERF1 as an attractive therapeutic target for mCRC treatment.

The impact of PSRC1 overexpression on gene and transcript expression profiling in the livers of ApoE-/- mice fed a high-fat diet.

Our previous studies have confirmed that proline/serine-rich coiled-coil 1 (PSRC1) overexpression can regulate blood lipid levels and inhibit atherosclerosis (AS) development. In the current study, the gene and transcript expression profiles in the livers of ApoE-/- mice overexpressing PSRC1 were investigated. HiSeq X Ten RNA sequencing (RNA-seq) analysis was used to examine the differentially expressed genes (DEGs) and differentially expressed transcripts in the livers of PSRC1-overexpressing ApoE-/- and control mice. Then, Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on these DEGs and on long noncoding RNA (lncRNA) predicted target genes. A total of 1892 significant DEGs were identified: 1431 were upregulated (e.g., Cyp2a4, Obp2a, and Sertad4), and 461 were downregulated (e.g., Moxd1, Egr1, and Elovl3). In addition, 8184 significant differentially expressed transcripts were identified, 4908 of which were upregulated and 3276 of which were downregulated. Furthermore, 1106 significant differentially expressed lncRNAs were detected, 713 of which were upregulated and 393 of which were downregulated. Quantitative reverse transcription PCR (qRT-PCR) verified changes in 10 randomly selected DEGs. GO analyses showed that the DEGs and predicted lncRNA target genes were mostly enriched for actin binding and lipid metabolism. KEGG biological pathway analyses showed that the DEGs in the livers of PSRC1-overexpressing ApoE-/- mice were enriched in the mitogen-activated protein kinase (MAPK) pathway. These findings reveal that PSRC1 may affect liver actin polymerization and cholesterol metabolism-related genes or pathways. These mRNAs and lncRNAs may represent new biomarkers and targets for the diagnosis and therapy of lipid metabolism disturbance and AS.

Association between the expression of secreted phosphoprotein - related genes and prognosis of human cancer.

BACKGROUND: While many studies have assessed the predictive value of secreted phosphoprotein (SPP) genes in cancer, the findings have been inconsistent. To resolve these inconsistencies, we systematically analyzed the available data to determine whether SPP1 and SPP2 are prognostic markers in the context of human cancer. METHODS: The expression of SPP1 and SPP2 was assessed by Oncomine analysis. The PrognoScan database was used to assess the prognostic value of SPP1 and SPP2, with cBioPortal used to assess copy number variations. The STRING database was used to generate a Protein - Protein Interaction (PPI) network for SPP genes. RESULTS: SPP1 was more likely to be over-expressed in breast, bladder, colorectal, head, neck, liver, lung, and esophageal cancers. SPP2 was expressed at lower levels in colorectal cancer, leukemia, liver cancer and pancreatic cancer. In addition, SPP1 and SPP2 mutations mainly occurred in cutaneous melanoma and endometrial cancer. CONCLUSIONS: Our results suggest that SPP1 and SPP2 may be effective therapeutic or diagnostic targets in certain cancers. Further research is required to confirm these results and verify the value of SPP1 and SPP2 as clinical markers of cancer prognosis.

Phosphoproteomic profiling of oxycodone­treated spinal cord of rats with cancer­induced bone pain.

Treatment of cancer­induced bone pain (CIBP) is challenging in clinical settings. Oxycodone (OXY) is used to treat CIBP; however, a lack of understanding of the mechanisms underlying CIBP limits the application of OXY. In the present study, all rats were randomly divided into three groups: The sham group, the CIBP group, and the OXY group. Then, a rat model of CIBP was established by inoculation of Walker 256 tumor cells from rat tibia. Phosphoproteomic profiling of the OXY­treated spinal dorsal cords of rats with CIBP was performed, and 1,679 phosphorylated proteins were identified, of which 160 proteins were significantly different between the CIBP and sham groups, and 113 proteins were significantly different between the CIBP and OXY groups. Gene Ontology analysis revealed that these proteins mainly clustered as synaptic­associated cellular components; among these, disks large homolog 3 expression was markedly increased in rats with CIBP and was reversed by OXY treatment. Subsequent domain analysis of the differential proteins revealed several significant synaptic­associated domains. In conclusion, synaptic­associated cellular components may be critical in OXY­induced analgesia in rats with CIBP.

[Features of the Structure and Expression of NPM and NCL Genes in Cutaneous Melanoma].

Malignant cutaneous melanoma (CM) is an extremely aggressive cancer characterized by a high level of metastatic activity and unfavorable prognosis due to a high incidence of relapses, as well as resistance to standard chemotherapy. Cutaneous melanoma accounts for 80% of deaths from malignant skin tumors. Nucleolin/C23 and nucleophosmin/B23, which constitute altogether ~70% of the nucleolus volume, are promising targets for molecular therapy of melanoma. These proteins perform many important functions in the cell, so disruption of the NCL and/or NPM gene structure and abnormal expression of the C23 and B23 proteins they encode, can lead to unlimited cell proliferation and progression of a tumor. Therefore, investigation of the structure and expression of these genes is a topical problem, which is important for understanding the mechanisms of CM carcinogenesis and for the development of new therapeutic approaches. This paper describes new NCL and NPM polymorphisms, as well as the levels of C23 and B23 expression in normal tissues, CM and mucosal melanoma.

AS1411-conjugated gold nanoparticles affect cell proliferation through a mechanism that seems independent of nucleolin.

G-rich oligonucleotide, AS1411, has been shown to interact with nucleolin and to inhibit cancer cell proliferation and tumor growth. This antiproliferative action is increased when AS1411 is conjugated to different types of nanoparticles. However, the molecular mechanisms are not known. In this work, we show in several cell lines that optimized AS1411-conjugated gold nanoparticles (GNS-AS1411) inhibit nucleolin expression at the RNA and protein levels. We observed an alteration of the nucleolar structure with a decrease of ribosomal RNA accumulation comparable to what is observed upon nucleolin knock down. However, the expression of genes involved in cell cycle and the cell cycle blockage by GNS-AS1411 are not regulated in the same way as that in cells where nucleolin has been knocked down. These data suggest that the anti-proliferative activity of GNS-AS1411 is not the only consequence of nucleolin targeting and down-regulation.

Large-scale Discovery of Substrates of the Human Kinome.

Kinase networks are important for cellular signal transduction. Despite tremendous efforts to uncover these signaling pathways, huge numbers of uncharacterized phosphosites still remain in the human proteome. Because of the transient nature of kinase-substrate interactions in vivo, it is almost impossible to identify direct substrates. Here, we present a strategy for the rapid, accurate and high-throughput discovery of in vitro kinase substrates using quantitative proteomics. Using 385 purified kinases (354 wild-type protein kinases, 21 mutants and 10 lipid kinases), we identified a total of 175,574 potential direct kinase substrates. In addition, we identified novel kinase groups, such as one group containing 30 threonine-directed kinases and another containing 15 serine/threonine/tyrosine kinases. Surprisingly, we observed that the diversity of substrates for tyrosine kinases was much higher than that for serine-threonine kinases.

Alteration of testicular regulatory and functional molecules following long-time exposure to 900 MHz RFW emitted from BTS.

The aim of this investigation was to evaluate changes in testosterone and some of the functional and regulatory molecules of testis such as P450scc, steroidogenic acute regulatory protein (StAR), tumour necrosis factor-α (TNF-α), interleukin-1α (IL-1α), interleukin-1ß (IL-1ß) and nerve growth factor (NGF) following exposure to 900 MHz radio frequency (RF). Thirty adult male Sprague Dawley rats (190 ± 20 g BW) were randomly classified in three equal groups, control (sham, without any exposure), short-time exposure (2 hr) (STE) and long-time exposure (4 hr) (LTE). The exposure was performed for 30 consecutive days. The testosterone level in both exposed groups was significantly less than control (p < .05). Level of TNF-α in both exposed groups was significantly greater than control (p < .05). IL-1α and NGF levels in LTE were significantly higher than the STE and control groups (p < .05). Level of IL-1ß in LTE was significantly higher than control (p < .05). Expression of both P450scc and StAR mRNA was significantly down-regulated in both exposed groups compared to control (p < .05). Our results showed that RFW can affect testis and reproductive function through changes in factors, which are important during steroidogenesis, and also through changes in inflammatory factors, which regulate Leydig cell functions.