LncRNA HCP5 Facilitates the Progression of Ovarian Cancer by Interacting with the PTBP1 Protein.

Ovarian cancer (OC) is a major gynecological malignancy with an annually increasing morbidity that poses a significant threat to the health of women worldwide. Most OC patients are diagnosed at an advanced stage. It is an urgent task to search for biomarkers for the diagnosis and treatment of OC. The lncRNA HCP5 (HCP5) was recently identified as an oncogene in several malignant tumors. However, the function of HCP5 in OC has rarely been reported. Herein, the levels of HCP5 and PTBP1 were found to be markedly increased in malignant OC tumor tissues and OC cell lines. In HCP5-silenced SKOV-3 and HEY cells, cell viability was markedly decreased, and the apoptosis rate was significantly increased, with more cells exhibiting G0/G1 arrest and increased expression of cleaved caspase-3 and cleaved caspase-9. Furthermore, the number of migrated cells, number of invaded cells, and migration distance were notably decreased by the knockdown of HCP5 in SKOV-3 cells and HEY cells. In the xenograft model established with SKOV-3 cells, the number of lung metastases, tumor growth, and Ki67 expression in tumor tissues were markedly decreased by the knockdown of HCP5, accompanied by an increased percentage of TUNEL-positive cells. HCP5 was found to be localized in the nucleus, and the interaction between HCP5 and PTBP1 was verified by RNA pull-down and RNA immunoprecipitation assays. Furthermore, in HCP5-overexpressing OC cells, the impacts of HCP5 on cell proliferation and apoptosis were significantly attenuated by the knockdown of PTBP1. Collectively, these results indicate that HCP5 facilitates the progression of OC by interacting with the PTBP1 protein.

Two plastidic glycolate/glycerate translocator 1 isoforms function together to transport photorespiratory glycolate and glycerate in rice chloroplasts.

The photorespiratory pathway is highly compartmentalized. As such, metabolite shuttles between organelles are critical to ensure efficient photorespiratory carbon flux. Arabidopsis plastidic glycolate/glycerate translocator 1 (PLGG1) has been reported as a key chloroplastic glycolate/glycerate transporter. Two homologous genes, OsPLGG1a and OsPLGG1b, have been identified in the rice genome, although their distinct functions and relationships remain unknown. Herein, our analysis of exogenous expression in oocytes and yeast shows that both OsPLGG1a and OsPLGG1b have the ability to transport glycolate and glycerate. Furthermore, we demonstrate in planta that the perturbation of OsPLGG1a or OsPLGG1b expression leads to extensive accumulation of photorespiratory metabolites, especially glycolate and glycerate. Under ambient CO2 conditions, loss-of-function osplgg1a or osplgg1b mutant plants exhibited significant decreases in photosynthesis efficiency, starch accumulation, plant height, and crop productivity. These morphological defects were almost entirely recovered when the mutant plants were grown under elevated CO2 conditions. In contrast to osplgg1a, osplgg1b mutant alleles produced a mild photorespiratory phenotype and had reduced accumulation of photorespiratory metabolites. Subcellular localization analysis showed that OsPLGG1a and OsPLGG1b are located in the inner and outer membranes of the chloroplast envelope, respectively. In vitro and in vivo experiments revealed that OsPLGG1a and OsPLGG1b have a direct interaction. Our results indicate that both OsPLGG1a and OsPLGG1b are chloroplastic glycolate/glycerate transporters required for photorespiratory metabolism and plant growth, and that they may function as a singular complex.

Generation of a caged lentiviral vector through an unnatural amino acid for photo-switchable transduction.

Application of viral vectors in gene delivery is attracting widespread attention but is hampered by the absence of control over transduction, which may lead to non-selective transduction with adverse side effects. To overcome some of these limitations, we proposed an unnatural amino acid aided caging-uncaging strategy for controlling the transduction capability of a viral vector. In this proof-of-principle study, we first expanded the genetic code of the lentiviral vector to incorporate an azido-containing unnatural amino acid (Nϵ-2-azidoethyloxycarbonyl-l-lysine, NAEK) site specifically within a lentiviral envelope protein. Screening of the resultant vectors indicated that NAEK incorporation at Y77 and Y116 was capable of inactivating viral transduction upon click conjugation with a photo-cleavable chemical molecule (T1). Exposure of the chimeric viral vector (Y77-T1) to UVA light subsequently removed the photo-caging group and restored the transduction capability of lentiviral vector both in vitro and in vivo. Our results indicate that the use of the photo-uncage activation procedure can reverse deactivated lentiviral vectors and thus enable regulation of viral transduction in a switchable manner. The methods presented here may be a general approach for generating various switchable vectors that respond to different stimulations and adapt to different viral vectors.

Prevalence and molecular characterization of methicillin-resistant Staphylococcus aureus with mupirocin, fusidic acid and/or retapamulin resistance.

BACKGROUND: The data on the prevalence of resistance to mupirocin (MUP), fusidic acid (FA) and retapamulin (RET) in methicillin-resistant Staphylococcus aureus (MRSA) from China are still limited. This study aimed to examine these three antibiotics resistance in 1206 MRSA clinical isolates from Eastern China. Phenotypic MUP, FA and RET resistance was determined by minimum inhibitory concentrations (MICs), and genotypic by PCR and DNA sequencing of the mupA/B, fusB-D, cfr, vgaA/Av/ALC/B/C/E, lsaA-C/E and salA and mutations in ileS, fusA/E, rplC, and 23S RNA V domain. The genetic characteristics of resistance isolates were conducted by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: Overall MRSA MUP, FA and RET resistance was low (5.1, 1.0 and 0.3%, respectively). MupA was the mechanism of high-level MUP resistance. All low-level MUP resistance isolates possessed an equivocal mutation N213D in IleS; of these, 2 reported an additional V588F mutation with an impact on the Rossman fold. FusA mutations, such as L461K, H457Q, H457Y and V90I were the primary FA mechanisms among high-level resistance isolates, most of which also contained fusC; however, all low-level resistance strains carried fusB. Except lsaE gene detected in one isolate, no other resistance mechanisms tested were found among RET-resistant isolates. Additionally, sixteen PFGE types (A-P) were observed, among which type B was the most common (49/76, 64.5%), followed by types E and G (4/76, 5.3% each) and types C and M (3/76, 3.9% each). All resistant strains were divided into 15 ST types by MLST. ST764 (24/76, 31.6%), ST630 (11/76, 14.5%), ST239 (9/76, 11.8%) and ST5 (7/76, 9.2%) were the major types. PFGE type B isolates with the aforementioned STs were mainly found in mupirocin resistant isolates. CONCLUSIONS: MUP, FA and RET exhibited highly activity against the MRSA isolates. Acquired genes and chromosome-borne genes mutations were responsible for MUP and FA resistance; however, the mechanism for some RET-resistant isolates remains to be further elucidated. Also, the surveillance to MUP in MRSA should be strengthened to prevent elevated resistance due to the expansion of clones.

Increasing prevalence of Neisseria gonorrhoeae with decreased susceptibility to ceftriaxone and resistance to azithromycin in Hangzhou, China (2015-17).

Objectives: Development of resistance in Neisseria gonorrhoeae to ceftriaxone monotherapy or ceftriaxone plus azithromycin dual therapy is a global public health concern. The aim of this study was to analyse the trend in antimicrobial resistance in Hangzhou, China, over the period 2015-17. Methods: In total, 379 clinical isolates were collected from seven hospitals and antimicrobial susceptibility was determined using the agar dilution method. Isolates showing resistance to ceftriaxone, azithromycin or cefixime were analysed for the presence of resistance determinants. STs were determined with the N. gonorrhoeae multiantigen sequence typing (NG-MAST) method and phylogenetic analysis and strain clustering was determined using porB and tbpB sequences. Results: Ceftriaxone resistance, decreased susceptibility to ceftriaxone and azithromycin resistance were observed in 3%, 17% and 21% of the isolates, respectively. This resulted in 5% of the isolates showing both decreased susceptibility to ceftriaxone and azithromycin resistance. Importantly, resistance levels to ceftriaxone and azithromycin increased over the study period, resulting in 5% ceftriaxone resistance, 27% decreased susceptibility to ceftriaxone and 35% azithromycin resistance in 2017 and 11% of the isolates showing both decreased susceptibility to ceftriaxone and azithromycin resistance. Phylogenetic and cluster analysis showed the emergence and expansion in 2017 of a clonally related cluster containing strains with high abundance of decreased susceptibility to ceftriaxone and/or cefixime, which was related to the presence of the mosaic penA allele X. Co-resistance to azithromycin was also observed in this cluster. Conclusions: Our findings have major implications for the future reliability of ceftriaxone monotherapy and ceftriaxone plus azithromycin dual therapy in China.

Interleukin-7 gene polymorphism rs766736182 associates with the risk of asthma in children.

BACKGROUND: Recently studies uncovered associations between polymorphisms of interleukin genes and the risk of asthma. However, the relationship between polymorphisms of interleukin-7 gene and the risk of children asthma has not been discovered yet. This study aims to investigate the relationship between single nucleotide polymorphisms (SNPs) on interleukin-7 gene and the risk of children asthma. METHODS: We genotyped eight SNPs of interleukin-7 gene in blood samples from 437 asthma patients and 489 healthy controls to analyze potential associations of these SNPs with the risk of asthma in children. RESULTS: A missense SNP rs766736182 (odds ratio (OR) = 2.185, 95% confidence interval (CI) = 1.561-2.252, P-value = 8.69468E-19) of the interleukin-7 gene is associated with the risk of children asthma. CONCLUSIONS: This study reveals that SNP rs766736182 of interleukin-7 is the risk factor for children asthma and implies potential role of immune system in the pathogenesis of children asthma.

The downregulation of miR-3173 in B-cell acute lymphoblastic leukaemia promotes cell invasion via PTK2.

MicroRNAs are important regulators of the pathogenesis of B-cell acute lymphoblastic leukaemia (B-ALL). In this study, we identified miR-3173 and its predicted target gene PTK2 were correspondingly differentially expressed in B-ALL patients. In B-ALL cell lines, CCK-8 proliferation assay revealed that miR-3173 could inhibit the cell proliferation. Moreover, transwell assay revealed that miR-3173 could also inhibit cell migration and invasion in B-ALL cell lines. Luciferase assays revealed that miR-3173 directly bound to the 3'untranslated region of PTK2, and western blotting showed that miR-3173 suppressed the expression of PTK2 at the protein level. Generally, this study indicates that miR-3173 negatively regulates PTK2 and inhibits proliferation and invasion of B-ALL cell lines. Thus, miR-3173 may represent a potential therapeutic molecule for B-ALL intervention.

Redirecting Killer T†Cells through Incorporation of Azido Sugars for Tethering Ligands.

The genetic expression of chimeric antigen receptors (CARs) on the surfaces of T cells enables the redirection of T cell specificity. To enhance the versatility of T cells as tumor-specific killers, we developed a nongenetic approach by which azide-containing sialic acids were metabolically incorporated into T cells to modify cellular sialyl glycans. After successful display of these moieties on the T cells, small-molecule ligands such as RGD and folate (as proof-of-concept, rather than supersized antibodies) were clicked orthogonally, leading to highly selective time- and dose-dependent cytotoxicity to integrin αv ß3 - and folate-receptor-positive cells, respectively. This chemical approach provides a facile platform for rational design of tumor-specific cytotoxic T cells for targeted immunotherapy.

Broadening the versatility of lentiviral vectors as a tool in nucleic acid research via genetic code expansion.

With the aim of broadening the versatility of lentiviral vectors as a tool in nucleic acid research, we expanded the genetic code in the propagation of lentiviral vectors for site-specific incorporation of chemical moieties with unique properties. Through systematic exploration of the structure-function relationship of lentiviral VSVg envelope by site-specific mutagenesis and incorporation of residues displaying azide- and diazirine-moieties, the modifiable sites on the vector surface were identified, with most at the PH domain that neither affects the expression of envelope protein nor propagation or infectivity of the progeny virus. Furthermore, via the incorporation of such chemical moieties, a variety of fluorescence probes, ligands, PEG and other functional molecules are conjugated, orthogonally and stoichiometrically, to the lentiviral vector. Using this methodology, a facile platform is established that is useful for tracking virus movement, targeting gene delivery and detecting virus-host interactions. This study may provide a new direction for rational design of lentiviral vectors, with significant impact on both basic research and therapeutic applications.

Site-Specific PEGylated Adeno-Associated Viruses with Increased Serum Stability and Reduced Immunogenicity.

Adeno-associated virus (AAV) is one of the most extensively studied and utilized viral vectors in clinical gene transfer research. However, the serum instability and immunogenicity of AAV vectors significantly limit their application. Here, we endeavored to overcome these limitations by developing a straightforward approach for site-specific PEGylation of AAV via genetic code expansion. This technique includes incorporation of the azide moiety into the AAV capsid protein followed by orthogonal and stoichiometric conjugation of a variety of polyethylene glycols (PEGs) through click chemistry. Using this approach, only the chosen site(s) was consistently PEGylated under mild conditions, preventing nonselective conjugation. Upon a series of in vitro examinations, AAVs conjugated with 20-kD PEG at sites Q325+1, S452+1, and R585+1 showed a 1.7- to 2.4-fold stability improvement in pooled human serum and a nearly twofold reduction in antibody recognition. Subsequent animal research on Sprague Dawley rats displayed a promising 20% reduction in antibody inducement and a higher virus titer in the blood. Together, our data demonstrate successful protection of an AAV vector from antibody neutralization and blood clearance, thereby increasing the efficiency of therapeutic gene delivery.

Re-exploration of the Codon Context Effect on Amber Codon-Guided Incorporation of Noncanonical Amino Acids in Escherichia coli by the Blue-White Screening Assay.

The effect of codon context on amber codon-guided incorporation of noncanonical amino acids (NAAs) has been previously examined by antibiotic selection. Here, we re-explored this effect by screening a library in which three nucleotides upstream and downstream of the amber codon were randomised, and inserted within the lacZ-α gene. Thousands of clones were obtained and distinguished by the depth of blue colour upon exposure to X-gal. Large-scale sequencing revealed remarkable preferences in nucleotides downstream of the amber codon, and moderate preferences for upstream nucleotides. Nucleotide preference was quantified by a dual-luciferase assay, which verified that the optimum context for NAA incorporation, AATTAGACT, was applicable to different proteins. Our work provides a general guide for engineering amber codons into genes of interest in bacteria.

Gene Expression and Correlation of Pten and Fabp4 in Liver, Muscle, and Adipose Tissues of Type 2 Diabetes Rats.

BACKGROUND: The aim of this work was to study the Fabp4 and Pten gene expression and correlation in the liver, muscle, and adipose tissues of type 2 diabetes mellitus (T2DM) rats. MATERIAL AND METHODS: Male Wistar rats (8 weeks old) were randomly divided into 2 groups (n=12/group): a control group fed a normal diet for 8 weeks and an experimental group fed a high-fat, high-sugar diet for 8 weeks and that received 25 mg/kg streptozotocin by intraperitoneal injection to induce T2DM. The random blood glucose, fasting blood glucose, and fasting insulin levels were measured. The expression of Pten and Fabp4 in the liver, muscle, and epididymal adipose tissues was estimated by real-time quantitative PCR. Pearson correlation coefficient analysis was used to investigate the expression correlation between Pten and Fabp4 in T2DM rats. RESULTS: The gene expressions of Pten and Fabp4 in the liver, muscle, and adipose tissues of T2DM rats were all significantly higher than those in the control group (P<0.05). Pten was highly expressed in the muscles and Fabp4 was highly expressed in muscle and adipose tissues. Furthermore, expressions of Fabp4 and Pten in the muscle and adipose tissues of T2DM rats were positively correlated (P<0.05), but not in the liver. CONCLUSIONS: The increased expression of PTEN and FABP4 in the adipose and muscles of T2DM rats may play an important role in the insulin resistance of T2DM. However, the mechanism by which these 2 genes function in T2DM needs further study.

Nanoparticles meet electrospinning: recent advances and future prospects.

Nanofibres can be fabricated by various methods and perhaps electrospinning is the most facile route. In past years, electrospinning has been used as a synthesis technique and the fibres have been prepared from a variety of starting materials and show various properties. Recently, incorporating functional nanoparticles (NPs) with electrospun fibres has emerged as one of most exciting research topics in the field of electrospinning. When NPs are incorporated, on the one hand the NPs endow the electrospun fibres/mats novel or better performance, on the other hand the electrospun fibres/mats could preserve the NPs from corrosion and/or oxidation, especially for NPs with anisotropic structures. More importantly, electrospinning shows potential applications in self-assembly of nanoscale building blocks for generating new functions, and has some obvious advantages that are not available by other self-assembly methods, i.e., the obtained free-standing hybrid mats are usually flexible and with large area, which is favourable for their commercial applications. In this critical review, we will focus on the fabrication and applications of NPs-electrospun fibre composites and give an overview on this emerging field combining nanoparticles and electrospinning. Firstly, two main strategies for producing NPs-electrospun fibres will be discussed, i.e., one is preparing the NPs-electrospun fibres after electrospinning process that is usually combined with other post-processing methods, and the other is fabricating the composite nanofibres during the electrospinning process. In particular, the NPs in the latter method will be classified and introduced to show the assembling effect of electrospinning on NPs with different anisotropic structures. The subsequent section describes the applications of these NPs-electrospun fibre mats and nanocomposites, and finally a conclusion and perspectives of the future research in this emerging field is given.

Epidemic and virulence characteristic of Shigella spp. with extended-spectrum cephalosporin resistance in Xiaoshan District, Hangzhou, China.

BACKGROUND: Shigellae have become increasingly resistant to the extended-spectrum cephalosporin (ESC) worldwide and pose a great challenge to anti-infection treatment options. The purpose of this study was to determine the resistance, cephalosporin resistance mechanisms, virulence characteristic and genotype of ESC-resistant Shigella. METHODS: From 2008 to 2012, Shigella isolates collected from diarrhea patients were detected for antibiotics sensitivity by disk diffusion, cephalosporin resistance determinants and virulence genes using polymerase chain reaction (PCR) and genotyping through enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). RESULTS: A total of 356 Shigella isolates were gathered, and 198 (55.6%, 58 S. flexneri and 140 S. sonnei) were resistant to ESC. All ESC-resistant isolates were susceptible to imipenem, and only 0.5% isolate was resistant to piperacillin/tazobactam. ESC-resistant S. flexneri showed high degrees of resistance to ampicillin (100%), ampicillin/sulbactam (96.6%), piperacillin (100%), trimethoprim/sulfamethoxazole (74.1%), ciprofloxacin (74.1%), levofloxacin (53.4%), ceftazidime (58.6%) and cefepime (58.6%). ESC-resistant S. sonnei exhibited high resistance rates to ampicillin (100%), piperacillin (100%) and trimethoprim/sulfamethoxazole (96.4%). Cephalosporin resistance genes were confirmed in 184 ESC-resistant isolates. bla(CTX-M) types (91.8%, mainly bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-57)) were most prevalent, followed by bla(OXA-30) (26.3%). Over 99.0% ESC-resistant isolates harbored virulence genes ial, ipaH, virA and sen. However, set1 were more prevalent in ESC-resistant S. flexneri isolates than in S. sonnei isolates. ERIC-PCR results showed that 2 and 3 main genotypes were detected in ESC-resistant S. flexneri and S. sonnei, respectively. CONCLUSION: Our findings indicated that a high prevalence of ESC-resistant Shigella mediated mainly by bla(CTX-M) with stronger resistance and virulence, and the existence of specific clones responsible for these Shigella infection in the region studied.

An engineered influenza virus to deliver antigens for lung cancer vaccination.

The development of cancer neoantigen vaccines that prime the anti-tumor immune responses has been hindered in part by challenges in delivery of neoantigens to the tumor. Here, using the model antigen ovalbumin (OVA) in a melanoma model, we demonstrate a chimeric antigenic peptide influenza virus (CAP-Flu) system for delivery of antigenic peptides bound to influenza A virus (IAV) to the lung. We conjugated attenuated IAVs with the innate immunostimulatory agent CpG and, after intranasal administration to the mouse lung, observed increased immune cell infiltration to the tumor. OVA was then covalently displayed on IAV-CPG using click chemistry. Vaccination with this construct yielded robust antigen uptake by dendritic cells, a specific immune cell response and a significant increase in tumor-infiltrating lymphocytes compared to peptides alone. Lastly, we engineered the IAV to express anti-PD1-L1 nanobodies that further enhanced regression of lung metastases and prolonged mouse survival after rechallenge. Engineered IAVs can be equipped with any tumor neoantigen of interest to generate lung cancer vaccines.

Aptamer-programmable adeno-associated viral vectors as a novel platform for cell-specific gene transfer.

Adeno-associated viruses (AAVs) are commonly used for in vivo gene therapy. Nevertheless, the wide tropism that characterizes these vectors limits specific targeting to a particular cell type or tissue. Here, we developed new chemically modified AAV vectors (Nε-AAVs) displaying a single site substitution on the capsid surface for post-production vector engineering through biorthogonal copper-free click chemistry. We were able to identify AAV vectors that would tolerate the unnatural amino acid substitution on the capsid without disrupting their packaging efficiency. We functionalized the Nε-AAVs through conjugation with DNA (AS1411) or RNA (E3) aptamers or with a folic acid moiety (FA). E3-, AS1411-, and FA-AAVs showed on average a 3- to 9-fold increase in transduction compared with their non-conjugated counterparts in different cancer cell lines. Using specific competitors, we established ligand-specific transduction. In vivo studies confirmed the selective uptake of FA-AAV and AS1411-AAV without off-target transduction in peripheral organs. Overall, the high versatility of these novel Nε-AAVs might pave the way to tailoring gene therapy vectors toward specific types of cells both for ex vivo and in vivo applications.

Identification of hub genes associated with spermatogenesis by bioinformatics analysis.

Spermatogenesis is a complex process related to male infertility. Till now, the critical genes and specific mechanisms have not been elucidated clearly. Our objective was to determine the hub genes that play a crucial role in spermatogenesis by analyzing the differentially expressed genes (DEGs) present in non-obstructive azoospermia (NOA) compared to OA and normal samples using bioinformatics analysis. Four datasets, namely GSE45885, GSE45887, GSE9210 and GSE145467 were used. Functional enrichment analyses were performed on the DEGs. Hub genes were identified based on protein-protein interactions between DEGs. The expression of the hub genes was further examined in the testicular germ cell tumors from the TCGA by the GEPIA and validated by qRT-PCR in the testes of lipopolysaccharide-induced acute orchitis mice with impaired spermatogenesis. A total of 203 DEGs including 34 up-regulated and 169 down-regulated were identified. Functional enrichment analysis showed DEGs were mainly involved in microtubule motility, the process of cell growth and protein transport. PRM2, TEKT2, FSCN3, UBQLN3, SPATS1 and GTSF1L were identified and validated as hub genes for spermatogenesis. Three of them (PRM2, FSCN3 and TEKT2) were significantly down-regulated in the testicular germ cell tumors and their methylation levels were associated with the pathogenesis. In summary, the hub genes identified may be related to spermatogenesis and may act as potential therapeutic targets for NOA and testicular germ cell tumors.

Arsenic induced progesterone production in a caspase-3-dependent manner and changed redox status in preovulatory granulosa cells.

Arsenic contamination is a principal environmental health threat throughout the world. However, little is known about the effect of arsenic on steroidogenesis in granulosa cells (GCs). We found that the treatment of preovulatory GCs with arsenite stimulated progesterone production. A significant increase in serum level of progesterone was observed in female Sprague-Dawley rats following arsenite treatment at a dose of 10 mg/L/rat/day for 7 days. Further experiments demonstrated that arsenite treatment did not change the level of intracellular cyclic AMP (cAMP) or phosphorylated ERK1/2 in preovulatory GCs; however, progesterone production was significantly decreased when cAMP-dependent protein kinase (PKA) or ERK1/2 pathway was inhibited. This implied that the effect of arsenite on progesterone production may require cAMP/PKA and ERK1/2 signaling but not depend on them. Furthermore, we found that arsenite decreased intracellular reactive oxygen species (ROS) but increased the antioxidant glutathione (GSH) levels and mitochondrial membrane potential (ΔΨm) in parallel to the changes in progesterone production. Progesterone antagonist blocked the arsenic-stimulated increase of GSH levels. Arsenite treatment induced caspase-3 activation, although no apoptosis was observed. Inhibition of caspase-3 activity significantly decreased progesterone production stimulated by arsenite or follicle-stimulating hormone (FSH). GSH depletion with buthionine sulfoximine led to cell apoptosis in response to arsenite treatment. Collectively, this study demonstrated for the first time that arsenite stimulates progesterone production through cleaved/active caspase-3-dependent pathway, and the increase of GSH level promoted by progesterone production may protect GCs against apoptosis and maintain the steroidogenesis of GCs in response to arsenite treatment.

Role of spastin and protrudin in neurite outgrowth.

Hereditary spastic paraplegia (HSP) is a neurodegenerative disorder characterized by retrograde axonal degeneration that primarily affects long spinal neurons. The gene encoding spastin has a well-established association with HSP, and protrudin is a known binding partner of spastin. Here, we demonstrate that the N-terminal domain of protrudin mediates the interaction with spastin, which is responsible for neurite outgrowth. We show that spastin promotes protrudin-dependent neurite outgrowth in PC12 cells. To further confirm these physiological functions in vivo, we microinjected zebrafish embryos with various protrudin/spastin mRNA and morpholinos. The results suggest that the spinal cord motor neuron axon outgrowth of zebrafish is regulated by the interaction between spastin and protrudin. In addition, the putative HSP-associated protrudinG191V mutation was shown to alter the subcellular distribution and impair the yolk sac extension of zebrafish, but without significant defects in neurite outgrowth both in PC12 cells and zebrafish. Taken together, our findings indicate that protrudin interacts with spastin and induces axon formation through its N-terminal domain. Moreover, protrudin and spastin may work together to play an indispensable role in motor axon outgrowth.