The Arabidopsis Mitochondrial Nucleoid-Associated Protein WHIRLY2 Is Required for a Proper Response to Salt Stress

In the last years, plant organelles have emerged as central coordinators of responses to internal and external stimuli, which can induce stress. Mitochondria play a fundamental role as stress sensors being part of a complex communication network between the organelles and the nucleus. Among the different environmental stresses, salt stress poses a significant challenge and requires efficient signaling and protective mechanisms. By using the why2 T-DNA insertion mutant and a novel knock-out mutant prepared by CRISPR/Cas9-mediated genome editing, this study revealed that WHIRLY2 is crucial for protecting mitochondrial DNA (mtDNA) integrity during salt stress. Loss-of-function mutants show an enhanced sensitivity to salt stress. The disruption of WHIRLY2 causes the impairment of mtDNA repair that results in the accumulation of aberrant recombination products, coinciding with severe alterations in nucleoid integrity and overall mitochondria morphology besides a compromised redox-dependent response and misregulation of antioxidant enzymes. The results of this study revealed that WHIRLY2-mediated structural features in mitochondria (nucleoid compactness and cristae) are important for an effective response to salt stress.

Elaborating the Iodine/Polyiodide Equilibrium Effects in Nanoporous Carbon-based Battery Electrode via Extreme Mass Asymmetry in Hybrid Cells

This article discusses the conversion of electrodeposited iodine to polyiodides within the nanopores of carbon electrodes that affect the performance of iodide electrolyte-based electrochemical cells. Here, carbon electrodes have been polarized in aqueous sodium iodide electrolyte to store charge in the form of solid iodine via highly reversible reaction (2I-⇌I2+2e-). The stored iodine within the pores interacts with free iodide ions present in the bulk electrolyte via comproportionation reactions leading to polyiodide (I3 - and I5 -) formations. By tuning the mass asymmetry of carbon electrodes in hybrid cells and using the in-situ Raman spectroscopy on positive battery electrode, we show the influence of iodine/polyiodides equilibrium shifts on the self-discharge and voltage rebounds during open circuit conditions. This study provides insights into the charging mechanisms of carbon electrodes for iodine-based hybrid supercapacitors and battery systems.

Application of Aptamers Improves CRISPR-Based Live Imaging of Plant Telomeres

Development of live imaging techniques for providing information how chromatin is organized in living cells is pivotal to decipher the regulation of biological processes. Here, we demonstrate the improvement of a live imaging technique based on CRISPR/Cas9. In this approach, the sgRNA scaffold is fused to RNA aptamers including MS2 and PP7. When the dead Cas9 (dCas9) is co-expressed with chimeric sgRNA, the fluorescent coat protein-tagged for MS2 and PP7 aptamers (tdMCP-FP and tdPCP-FP) are recruited to the targeted sequence. Compared to previous work with dCas9:GFP, we show that the quality of telomere labeling was improved in transiently transformed Nicotiana benthamiana using aptamer-based CRISPR-imaging constructs. Labeling is influenced by the copy number of aptamers and less by the promoter types. The same constructs were not applicable for labeling of repeats in stably transformed plants and roots. The constant interaction of the RNP complex with its target DNA might interfere with cellular processes.

Two combinatorial patterns of telomere histone marks in plants with canonical and non-canonical telomere repeats

Telomeres, nucleoprotein structures at the ends of linear eukaryotic chromosomes, are crucial for the maintenance of genome integrity. In most plants, telomeres consist of conserved tandem repeat units comprising the TTTAGGG motif. Recently, non-canonical telomeres were described in several plants and plant taxons, including the carnivorous plant Genlisea hispidula (TTCAGG/TTTCAGG), the genus Cestrum (Solanaceae; TTTTTTAGGG), and plants from the Asparagales order with either a vertebrate-type telomere repeat TTAGGG or Allium genus-specific CTCGGTTATGGG repeat. We analyzed epigenetic modifications of telomeric histones in plants with canonical and non-canonical telomeres, and further in telomeric chromatin captured from leaves of Nicotiana benthamiana transiently transformed by telomere CRISPR-dCas9-eGFP, and of Arabidopsis thaliana stably transformed with TALE_telo C-3×GFP. Two combinatorial patterns of telomeric histone modifications were identified: (i) an Arabidopsis-like pattern (A. thaliana, G. hispidula, Genlisea nigrocaulis, Allium cepa, Narcissus pseudonarcissus, Petunia hybrida, Solanum tuberosum, Solanum lycopersicum) with telomeric histones decorated predominantly by H3K9me2; (ii) a tobacco-like pattern (Nicotiana tabacum, N. benthamiana, C. elegans) with a strong H3K27me3 signal. Our data suggest that epigenetic modifications of plant telomere-associated histones are related neither to the sequence of the telomere motif nor to the lengths of the telomeres. Nor the phylogenetic position of the species plays the role; representatives of the Solanaceae family are included in both groups. As both patterns of histone marks are compatible with fully functional telomeres in respective plants, we conclude that the described specific differences in histone marks are not critical for telomere functions.

Live-Cell CRISPR Imaging in Plant Cells with a Telomere-Specific Guide RNA

Chromatin organization is highly dynamic in living cells. Therefore, it might have a regulatory role over biological mechanisms like transcription, replication, and DNA repair. To elucidate how these mechanisms are regulated, it is required to establish imaging methods to visualize the chromatin dynamic in living cells. Here, we provide a protocol for a live plant cell imaging technique based on application of two orthologs of the bacterial clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) from Streptococcus pyogenes and Staphylococcus aureus. This technique uses the inactive variants of Cas9 combined with different fluorescent proteins (GFP and mRuby) and telomere-specific guide RNA to target telomeric repeats in Nicotiana benthamiana. Our immuno-FISH data revealed that signals arising from the CRISPR/dCas9 method are specifically belonging to telomeric regions.

RNA-guided endonuclease - in situ labelling (RGEN-ISL): a fast CRISPR/Cas9-based method to label genomic sequences in various species

Visualising the spatio-temporal organisation of the genome will improve our understanding of how chromatin structure and function are intertwined. We developed a tool to visualise defined genomic sequences in fixed nuclei and chromosomes based on a two-part guide RNA with a recombinant Cas9 endonuclease complex. This method does not require any special construct or transformation method. In contrast to classical fluorescence in situ hybridiaztion, RGEN-ISL (RNA-guided endonuclease - in situ labelling) does not require DNA denaturation, and therefore permits a better structural chromatin preservation. The application of differentially labelled trans-activating crRNAs allows the multiplexing of RGEN-ISL. Moreover, this technique is combinable with immunohistochemistry. Real-time visualisation of the CRISPR/Cas9-mediated DNA labelling process revealed the kinetics of the reaction. The broad range of adaptability of RGEN-ISL to different temperatures and combinations of methods has the potential to advance the field of chromosome biology.

Higher intake of dietary n-3 PUFA and lower MUFA are associated with fewer menopausal symptoms

OBJECTIVE

This study aimed to investigate the association between dietary fat quality and menopausal symptoms.

METHODS

We carried out a cross-sectional study with 393 Iranian postmenopausal women. Dietary intakes and menopausal symptoms were assessed, using a validated food frequency questionnaire and a menopausal rating scale (MRS) questionnaire, respectively. Participants were divided into low and high total MRS and its domain scores.

RESULTS

Women in the highest quartiles of monounsaturated fatty acids (MUFA) had higher somatic symptoms compared with women in the lowest quartile (odds ratio [OR] 3.41; 95% confidence interval [CI] 1.17-9.95). Women in the highest quartiles of n-3 polyunsaturated fatty acids (PUFA) (OR 0.58; 95% CI 0.32-1.05), eicosapentaenoic acid (EPA) (OR 0.66; 95% CI 0.37-1.20), and n-3:n-6 PUFA ratio (OR 0.49; 95% CI 0.25-0.97) had lower somatic symptoms compared to the lowest quartiles. The OR for psychological symptoms decreased from the lowest to the highest quartiles of n-3 PUFA (OR 0.47; 95% CI 0.20-1.11) and n-3:n-6 PUFA ratio (OR 0.46; 95% CI 0.24-0.86). Higher intakes of EPA (OR 0.53; 95% CI 0.29-0.99) and docosahexaenoic acid (OR 0.51; 95% CI 0.27-0.95) were found to be related with fewer urogenital symptoms.

CONCLUSION

Consuming diets low in MUFA intake, but high in n-3 PUFA, and with a more favorable ratio of n-3:n-6 PUFA may be helpful for improving menopausal symptoms.

HLA-G gene 14-bp deletion variant protects Iranian subjects against chronic hepatitis B infection

To investigate whether 14-bp Ins/Del polymorphism in HLA-G gene is associated with the risk of chronic hepatitis B (CHB) infection. This study was performed on a total of 396 individuals including 199 CHB patients and 197 healthy subjects from a south-east Iranian population. We genotyped 14-bp Ins/Del polymorphism in the HLA-G gene using polymerase chain reaction method. The results of our study revealed that the HLA-G 14-bp deletion polymorphism was associated with a reduced risk of CHB at both allele and genotypic levels. The 14-bp Del allele and Ins/Del genotype were more frequent in control group than in CHB patients (37% vs 28% for Del allele with OR = 0.68 and p-value = .015; 73% vs 52% for Ins/Del genotype with OR = 0.43 and p-value = .001) and both were protective factors against CHB. However, no difference was found in the distribution of HLA-G 14-bp genotypes among subjects with varied levels of HBV DNA or hepatic enzymes (p > .05). Our findings, for the first time, suggest that the HLA-G 14-bp Ins/Del polymorphism may be a marker for genetic susceptibility to CHB infection.

Biotechnological advances in Lilium

Modern powerful techniques in plant biotechnology have been developed in lilies (Lilium spp., Liliaceae) to propagate, improve and make new phenotypes. Reliable in vitro culture methods are available to multiply lilies rapidly and shorten breeding programs. Lilium is also an ideal model plant to study in vitro pollination and embryo rescue methods. Although lilies are recalcitrant to genetic manipulation, superior genotypes are developed with improved flower colour and form, disease resistance and year round forcing ability. Different DNA molecular markers have been developed for rapid indirect selection, genetic diversity evaluation, mutation detection and construction of Lilium linkage map. Some disease resistance-QTLs are already mapped on the Lilium linkage map. This review presents latest information on in vitro propagation, genetic engineering and molecular advances made in lily.

Disease progression and patient survival are significantly influenced by BRAF protein expression in primary melanoma

BACKGROUND

Mutation of BRAF is a prevalent event in melanoma. Despite much attention to the role of BRAF mutation in melanoma, the status of BRAF protein expression and its significance in melanoma progression are unknown.

OBJECTIVES

We investigated the BRAF expression level in different stages of melanocytic lesions and evaluated its correlation with clinicopathological features and patient survival.

METHODS

Using tissue microarray, BRAF expression and its correlation with patient outcome was evaluated in 49 naevi samples and 370 patients with melanoma. We also evaluated the correlation of BRAF protein expression and V600E mutation using direct sequencing.

RESULTS

Compared with naevi samples, BRAF expression was remarkably increased in primary melanomas and further increased in metastatic melanomas (P = 1·8 × 10(-11) ). High BRAF expression was significantly correlated with thicker tumours, ulceration and higher American Joint Committee on Cancer stages (P = 1·5 × 10(-7) , 1·5 × 10(-5) and 3·6 × 10(-13) , respectively). In cases of primary melanoma, patients with high BRAF expression had significantly worse overall (P = 0·009) and disease-specific 5-year survival (P = 0·007). While there was a trend for higher prevalence of BRAF V600E mutation in patients with high BRAF protein expression, no significant correlation was observed between protein expression and BRAF mutation. Furthermore, univariate Cox regression analysis confirmed high BRAF protein expression as a strong risk factor for poor patient survival in primary melanoma [hazard ratio (HR) 2·08 for overall survival; HR 2·39 for disease-specific survival].

CONCLUSIONS

Our data demonstrate that BRAF protein expression is significantly increased during melanoma progression. In addition, we revealed a novel prognostic value for BRAF protein expression in primary melanoma as it is significantly correlated with poor patient survival.

Hepatitis B core antibody in blood donor in Sistan-Balutuestan province of Iran

BACKGROUND

Safety of blood donor is an important issue for a recipient of blood so all blood donors are to screened for viral such as HBV, HCV, and HIV. Nevertheless, infections sometime occur by blood and its products.

OBJECTIVE

Because we haven't got any awareness about isolated Hbc Ab from a blood donor who presented of occults B hepatitis which can transmit infection to blood recipient, we decided to evaluate HbcAb in a blood donor in this province.

MATERIALS AND METHODS

This is a cross-sectional study on a blood donor in Sistan-Balutuestan province in southeast of Iran in 2010. All individuals referred for blood donation recruited to this. After consent demographic data was recorded from each case, 5 ml blood sample was drawn and centrifuged to separate out the serum and then HbsAb, HbcAb was assayed. Data analyzed by SPSS 16 and frequency, chi- square test, and Fisher exact test was used and if P > 0.05 it was accented as significant association.

RESULT

All individuals were men with age 55 10.5 years. The number of people who had free job was 149 (34.6%) and the number of people whose education level was diploma was 159 (36.9%). About 423 (98.1%) lived in urban areas. The mean weight of men was 76.6 13.7; about 259 (60.1%) men were married. A total of 22 (5.1%) had a positive smoking history. HBc Ab was positive in 87 (20.2%). Nearly all people had HBsAb titer more than 10 IU/L.

CONCLUSION

This study showed that some of the blood donors had isolated HbcAb positive therefore we recommend HbcAb screening for blood donation.

Role of EIF5A2, a downstream target of Akt, in promoting melanoma cell invasion

BACKGROUND

Cutaneous melanoma is a life-threatening skin cancer because of its poorly understood invasive nature and high metastatic potential. This study examines the importance of eukaryotic translation initiation factor 5A2 (EIF5A2) in melanoma pathogenesis.

METHODS

We examined EIF5A2 expression in 459 melanocytic lesions using tissue microarray. In addition, melanoma cell lines were subjected to invasion and cell proliferation assays, zymography, FACS and real-time PCR to investigate the role of EIF5A2 in cancer progression.

RESULTS

Positive EIF5A2 staining increased from dysplastic naevi to primary melanomas (PMs; P=0.001), and further increased in metastatic melanomas (P=0.044). Eukaryotic translation initiation factor 5A2 expression was correlated with melanoma thickness (P<0.001) and was inversely correlated with the 5-year survival of PM patients especially those with tumour ≤2 mm thick. Strikingly, none of the latter died within 5 years in EIF5A2-negative staining group. Cox regression analysis revealed that EIF5A2 is an independent prognostic marker. Further, we found that EIF5A2 is a novel downstream target of phosphorylated Akt. Both melanoma cell invasion and MMP-2 activity increased and decreased with EIF5A2 overexpression and knockdown, respectively.

CONCLUSION

We for the first time showed that EIF5A2, as a target of PI3K/Akt, promotes melanoma cell invasion and may serve as a promising prognostic marker and a potential therapeutic target for melanoma.

Seroepidemiology of HBV infection in South-East of iran; a population based study

BACKGROUND

Hepatitis B virus (HBV) infection is a major risk factor of cirrhosis and hepatocellular carcinoma affecting billions of people globally. Since information on its prevalence in general population is mandatory for formulating effective policies, this population based serological survey was conducted in Sistan and Baluchistan, where no previous epidemiological data were available.

METHODS

Using random cluster sampling 3989 healthy subjects were selected from 9 districts of Sistan and Baluchistan Province in southeastern Iran. The subjects' age ranged from 6 to 65 years old. Serum samples were tested for HBcAb, HBsAg. Screening tests were carried out by the third generation of ELISA. Various risk factors were recorded and multivariate analysis was performed.

RESULTS

The prevalence of HBsAg and HBcAb in Sistan and Baluchistan was 3.38% (95% CI 2.85; 3.98) and 23.58% (95% CI 22.29; 24.93) respectively. We found 8 cases of positive anti-HDV antibody. Predictors of HBsAg or HBcAb in multivariate analysis were age, marital status and addiction.

CONCLUSION

The rate of HBV infection in Sistan and Baluchistan was higher than other parts of Iran. Approximately 25% of general population in this province had previous exposure to HBV and 3% were HBsAg carriers. Intrafamilial and addiction were major routes of HBV transmission in this province.

In vitro propagation of Lilium longiflorum var. ceb-dazzle through direct somatic embryogenesis

Experiments were carried out to investigate the effects of various concentrations of Picloram (0, 1, 2, 3, 6 and 9 mg L(-1)), TDZ (0, 0.5, 1, 1.5 and 2 mg L(-1)), NAA (1.5 mg L(-1)) in combination with TDZ (0.08, 0.2 and 0.4 mg L(-1)), 2,4-D (2.5, 5 and 10 mg L(-1)) combined with BAP (0.25 mg L(-1)) and different types of explants (basal, central and distal part of the bulb scale) on direct somatic embryogenesis induction of Lilium longiflorum var. Ceb-Dazzle. The explants were surface sterilized and cultured on MS medium supplemented with 3% sucrose, 0.3% Phytagel and various concentrations of mentioned growth regulators. It was found that Picloram at a concentration of 2 mg L-' was the most effective treatment for induction of direct somatic embryogenesis and gave the highest number of embryos (18.6) on each explant. The explants from basal part of the bulb scale showed the best responses (19.9 embryos/explant). TDZ alone or combined with NAA in various concentrations was not able to induce somatic embryogenesis, but gave direct bulblet regeneration. Similar results were obtained for 2, 4-D and BAP combination treatments. Induced somatic embryos were transferred to MS medium without growth regulators for maturation and matured plantlets were successfully acclimatized and transferred to in vivo conditions.

In vivo and in vitro induction of 2'-5' oligoadenylate synthetase by interferon-alpha in nodular non-Hodgkin's lymphoma and correlations with the clinical response

We investigated the correlations between the in vivo-in vitro induction of 2'-5' oligoadenylate synthetase (2-5A synthetase) by IFN-alpha in cells isolated from patients with low-grade nodular non-Hodgkin's lymphoma (NHL) and subsequent clinical responses of these patients to IFN-alpha therapy. Eleven patients were treated daily with 9 x 10(6) U of IFN-alpha 2a in a phase II trial. After an eight week treatment, four patients achieved complete remission, one a partial response, one a minor response, and five failed to respond. Basal levels of 2-5A synthetase in lymph node tumor B cells and peripheral blood mononuclear cells (PBMC) isolated before therapy differed from patient to patient and were significantly lower than in PBMC from healthy donors (P less than 0.03). In vivo single injections of 9 x 10(6) U IFN-alpha 2a induced the 2-5A synthetase in PBMC from all patients to various degrees without quantitative relation to the clinical responses. Injection of a tenfold lower dose resulted in effects of similar extent in most cases. In vitro, IFN-alpha 2a induced the 2-5A synthetase in lymph node tumor B cells isolated before therapy, and the degree of induction was significantly higher in patients who proved to respond to therapy than in patients who displayed no or minor responses (P less than 0.013). This indicates that, in nodular NHL, the 2-5A synthetase assay may have some predictive value for responsiveness to IFN-alpha therapy.