Two novel variants of hop stunt viroid associated with yellow corky vein disease of sweet orange and split bark disorder of sweet lime

Yellow corky vein was reported as a graft-transmissible disease of lime in India. It was attributed to infection by hop stunt viroid (HSVd) and citrus exocortis viroid (CEVd). Recently similar symptoms have been observed in Washington navel orange in Jahrom and Darab in the Fars province of Iran. It is characterized by yellowing and suberization of veins followed by tree decline. Sweet lime split bark is another disorder of increasing importance in the Fars province. It is characterized by cracks in the bark of the main stem which may spread to branches of the tree. Since these symptoms resembled those of certain viroids, a study was undertaken to determine possible association of viroids with the disorders. Reverse transcription polymerase chain reaction (RT-PCR) followed by cloning and sequencing of PCR products and dot-blot hybridization were used to identify the viroids associated with the diseases. Comparison of molecular properties (nucleotide composition, primary and secondary structures, molecular weights, phylogenetic relationships and percent nucleotide similarity and difference) of viroid variants were carried out. It was found that a novel variant of hop stunt viroid (HSVd-sycv) was associated with yellow corky vein disease of Washington navel and another new variant (HSVd-sb) with split bark disorder of sweet lime. No other viroids were constantly detected. HSVd-sycv was closely related to noncachexia variant of hop stunt viroid (HSVd-cit) but only with 93.7% homology with HSVd-lycv. It differed in a single nucleotide from HSVd-cit, in the variable domain in the so-called “cachexia expression motif”. HSVd-sb had only 94.8% homology with a noncachexia variant of hop stunt viroid (CVd-IIa-117) which causes mild bark-cracking symptoms on Pomeroy trifoliate orange rootstocks. According to the performed molecular comparisons, HSVd-sb differed from CVd-IIa-117 in “cachexia expression motif” and probably severe cracks induced by HSVd-sb occurred because of variation in this motif. Keyword: HSVd, Sweet lime split bark, Sweet orange yellow corky vein, Citrus viroids, Viroid phylogen

Widespread occurrence of Tomato ring spot virus in deciduous fruit trees in Iran

Despite a long tradition of fruit-tree growing in all provinces of Iran, information on tree viruses in this country is scant. In the present study, presence of Tomato ring spot virus (ToRSV) was surveyed in various woody plants in this country by mechanical inoculation to herbaceous hosts, ELISA using a commercial antiserum, and PCR with specific primers. ToRSV was identified in the following plant-symptom combinations: Walnut with mottling, deformation, necrosis, and yellowing of main veins from Tehran Province; plum with yellowing of main veins, peach with yellowing of major veins and marginal necrosis, and hazelnut with interveinal chlorosis and marginal necrosis from Ardabil Province; apple with yellowing of main veins, mosaic and necrotic lesions, quince with large necrotic spots, and almond with leaf deformation and rosetting from Khorasan Province; and raspberry with marginal necrosis of leaf and necrotic lesions from Mazandaran Province. Mechanical inoculation from walnut, plum, peach, hazelnut, apple, quince, almond, and raspberry to Nicotiana tabacum cv. Samsun resulted in systemic infection. The virus isolates induced local lesions, leaf deformation, and necrosis in N. rustica, chlorotic local lesions on Chenopodium quinoa, and large local lesions on Gomphrena globosa. All samples were ELISA positive. PCR with specific primers resulted in the amplification of the expected fragment (490 bp). This study shows extensive occurrence of ToRSV in Iran.Keywords: Tomato ringspot virus, fruit tree viruses, Ira

Human leukocyte antigen class I (A, B) and class II (DRB1) allele and haplotype frequencies in Iranian patients with Buerger's disease

Objective: The aim of this study was to investigate the human leukocyte antigen (HLA) class I (HLA-A and HLA-B) and II (HLA-DRB1) allele and haplotype frequencies in a group of Iranian patients with Buerger's disease (BD) in comparison with a normal healthy control group. Methods: A total of 70 unrelated male patients and 100 healthy controls from Sina Hospital, Tehran, Iran, belonging to the same ethnic background, were enrolled in this case-control study. HLA-A, B, and DRB1 typing were performed by polymerase chain reaction with sequence-specific primers (PCR-SSP). Results: The results of this case-control study showed that the frequency of the HLA-A*03:01 (odds ratio (OR) = 2.88, P value (Pv) =.002), HLA-A*29:01 (OR = 15.31, Pv <.001), HLA-DRB1*04:02 (OR = 3.41, Pv <.001), and HLA-DRB1*16:01 (OR = 8.16, Pv <.001) was significantly higher in BD patients compared with healthy controls, whereas the frequency of the HLA-DRB1*01:01 (OR = 0.03, Pv <.001) was significantly lower in BD patients. The most frequent extended haplotypes in our patients were HLA-A*02:01-B*55:01-DRB1*04:03. Conclusion: This study is the first study evaluating an association between the HLA pattern and BD in the patients with BD from North West and North Iran. © 2020 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Lt

Comparative characterization of mesenchymal stem cells from eGFP transgenic and non-transgenic mice

Abstract Background Adipose derived- and bone marrow-derived murine mesenchymal stem cells (mMSCs) may be used to study stem cell properties in an in vivo setting for the purposes of evaluating therapeutic strategies that may have clinical applications in the future. If these cells are to be used for transplantation, the question arises of how to track the administered cells. One solution to this problem is to transplant cells with an easily identifiable genetic marker such as enhanced green fluorescent protein (eGFP). This protein is fluorescent and therefore does not require a chemical substrate for identification and can be visualized in living cells. This study seeks to characterize and compare adipose derived- and bone marrow-derived stem cells from C57Bl/6 mice and eGFP transgenic C57Bl/6 mice. Results The expression of eGFP does not appear to affect the ability to differentiate along adipogenic or osteogenic lineages; however it appears that the tissue of origin can influence differentiation capabilities. The presence of eGFP had no effect on cell surface marker expression, and mMSCs derived from both bone marrow and adipose tissue had similar surface marker profiles. There were no significant differences between transgenic and non-transgenic mMSCs. Conclusion Murine adipose derived and bone marrow derived mesenchymal stem cells from non-transgenic and eGFP transgenic C57Bl/6 mice have very similar characterization profiles. The availability of mesenchymal stem cells stably expressing a genetic reporter has important applications for the advancement of stem cell research.</p

The tissue-renin-angiotensin-system of the human intervertebral disc

Symptomatic intervertebral disc (IVD) degeneration accounts for significant socioeconomic burden. Recently, the expression of the tissue renin-angiotensin system (tRAS) in rat and bovine IVD was demonstrated. The major effector of tRAS is angiotensin II (AngII), which participates in proinflammatory pathways. The present study investigated the expression of tRAS in human IVDs, and the correlation between tRAS, inflammation and IVD degeneration. Human IVD tissue was collected during spine surgery and distributed according to principal diagnosis. Gene expression of tRAS components, proinflammatory and catabolic markers in the IVD tissue was assessed. Hydroxyproline (OHP) and glycosaminoglycan (GAG) content in the IVD tissue were determined. Tissue distribution of tRAS components was investigated by immunohistochemistry. Gene expression of tRAS components such as angiotensin-converting enzyme (ACE), Ang II receptor type 2 (AGTR2), angiotensinogen (AGT) and cathepsin D (CTSD) was confirmed in human IVDs. IVD samples that expressed tRAS components (n = 21) revealed significantly higher expression levels of interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 4 and 5 compared to tRAS-negative samples (n = 37). Within tRAS-positive samples, AGT, matrix-metalloproteinases 13 and 3, IL-1, IL-6 and IL-8 were more highly expressed in traumatic compared to degenerated IVDs. Total GAG/DNA content of non-tRAS expressing IVD tissue was significantly higher compared to tRAS positive tissue. Immunohistochemistry confirmed the presence of AngII in the human IVD. The present study identified the existence of tRAS in the human IVD and suggested a correlation between tRAS expression, inflammation and ultimately IVD degeneration

Telomere and telomerase in stem cells

Telomeres, guanine-rich tandem DNA repeats of the chromosomal end, provide chromosomal stability, and cellular replication causes their loss. In somatic cells, the activity of telomerase, a reverse transcriptase that can elongate telomeric repeats, is usually diminished after birth so that the telomere length is gradually shortened with cell divisions, and triggers cellular senescence. In embryonic stem cells, telomerase is activated and maintains telomere length and cellular immortality; however, the level of telomerase activity is low or absent in the majority of stem cells regardless of their proliferative capacity. Thus, even in stem cells, except for embryonal stem cells and cancer stem cells, telomere shortening occurs during replicative ageing, possibly at a slower rate than that in normal somatic cells. Recently, the importance of telomere maintenance in human stem cells has been highlighted by studies on dyskeratosis congenital, which is a genetic disorder in the human telomerase component. The regulation of telomere length and telomerase activity is a complex and dynamic process that is tightly linked to cell cycle regulation in human stem cells. Here we review the role of telomeres and telomerase in the function and capacity of the human stem cells