Epigenetic integrity of paternal imprints enhances the developmental potential of androgenetic haploid embryonic stem cells

The use of two inhibitors of Mek1/2 and Gsk3β (2i) promotes the generation of mouse diploid and haploid embryonic stem cells (ESCs) from the inner cell mass of biparental and uniparental blastocysts, respectively. However, a system enabling long-term maintenance of imprints in ESCs has proven challenging. Here, we report that the use of a two-step a2i (alternative two inhibitors of Src and Gsk3β, TSa2i) derivation/culture protocol results in the establishment of androgenetic haploid ESCs (AG-haESCs) with stable DNA methylation at paternal DMRs (differentially DNA methylated regions) up to passage 60 that can efficiently support generating mice upon oocyte injection. We also show coexistence of H3K9me3 marks and ZFP57 bindings with intact DMR methylations. Furthermore, we demonstrate that TSa2i-treated AG-haESCs are a heterogeneous cell population regarding paternal DMR methylation. Strikingly, AG-haESCs with late passages display increased paternal-DMR methylations and improved developmental potential compared to early-passage cells, in part through the enhanced proliferation of H19-DMR hypermethylated cells. Together, we establish AG-haESCs that can long-term maintain paternal imprints.

Characterization of Odontoblasts in Supernumerary Tooth-derived Dental Pulp Stem Cells between Passages by Real-Time PCR

The aim of this study is to compare the properties of odontoblast gene of early passage cells and late passage cells derived from impacted maxillary supernumerary teeth. Impacted supernumerary teeth with maxilla were extracted from 12 patients (8 males, 4 females) between 6 - 9 years old without medical history. Real-time polymerase chain reaction (PCR) was conducted to compare characterization of odontoblast cell in the 3rd and 10th passage, and between with bone inducing additive group and without additive group. Genes for odontoblasts characteristics are osteonectin (ONT), alkaline phosphatase (ALP), osteocalcin (OCN), dentin matrix protein 1 (DMP-1) and dentin sialophosphoprotein (DSPP). The level of gene expression was in a decreasing order of ONT, ALP, OCN, DMP-1 and DSPP in the 3rd passage, and in decreasing order of ONT, DMP-1, OCN, ALP, and DSPP in the 10th passage in the undifferentiation and differentiation group. The order of ONT, DMP-1, and OCN did not changed. ALP and DMP-1 were switched in order. ALP and DMP-1 may be used as important markers for differentiating between the 3rd passage and 10th passage cells. Considering that supernumerary tooth was extracted young age and the time required to cultured 10th passage was short, supernumerary tooth can be considered a useful donor site of dental pulp stem cells.

Puerarin blocks the aging phenotype in human dermal fibroblasts

Dermal fibroblast aging contributes to aging-associated functional defects in the skin since dermal fibroblasts maintain skin homeostasis by interacting with the epidermis and extracellular matrix. Here, we found that puerarin, an isoflavone present in Pueraria lobata (Kudzu), can prevent the development of the aging-phenotype in human dermal fibroblasts. Normal human dermal fibroblasts (NHDFs) were subcultivated and high-passage cells were selected as senescent cells, whereas low-passage cells were selected as a young cell control. Puerarin treatment increased cell proliferation and decreased the proportion of senescence-associated beta-galactosidase-positive cells in a high-passage culture of NHDFs. Moreover, puerarin treatment reduced the number of smooth muscle actin (SMA)-positive myofibroblasts and the expression of a reticular fibroblast marker, calponin 1 (CNN1), which were induced in high-passage NHDFs. Fulvestrant, an estrogen receptor antagonist, blocked the puerarin-mediated downregulation of SMA and CNN1. Our results suggest that puerarin may be a useful functional food that alleviates aging-related functional defects in dermal fibroblasts.

In Vitro Effect of Triamcinolone and Platelet-rich Plasma on Lateral Epicondylitis-derived Cells

Background: Lateral epicondylitis (LE) is a common musculoskeletal condition. However, the treatment of LE is still controversial. The present study evaluated the production of inflammatory cytokines by lateral epicondylitis-derived cells and compared the anti-inflammatory effect of triamcinolone acetonide with platelet-rich plasma (PRP) on their production in cell culture.Methods: Third passage cells from primary cultures of lateral epicondylitis were assessed for the production of the cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α by immune-enzymatic assay (ELISA), after treatment with 1, 10 and 100 mM triamcinolone compared to untreated controls at the time points 6, 12, 18, 24, 48, 72 and 96 hours, and to PRP at 48, 72 and 96 hours.Results: The cytokines IL-6 and IL-8 were produced in high concentrations by lateral epicondylitis cells. Triamcinolone induced a significant decrease in the production of IL-6 and IL-8 at 48, 72 and 96 hours, and at 12 hours for IL-8. The PRP group produced significantly higher levels of IL-8 than the control group, at 96 hours. There was a significant increase in IL-10 production with the use of 100 μM triamcinolone at 48 hours, compared to controls. The production of IL1-β and TNF-α was very low and did not change when the cultures were treated with triamcinolone or PRP.Conclusion: Our results demonstrated that IL-6 and IL-8 plays a role in the pathogenesis of lateral epicondylitis. Triamcinolone inhibited the production of the production of IL-6 and IL-8 by lateral epicondylitis-derived cells and PRP induced an increase in IL-8 levels compared to controls.

Root anatomy of Venezuelan species of Geonoma (Arecaceae: Arecoideae: Geonomateae)

In this research we studied root anatomy of eight species and two morphotypes from the genus Geonoma in Venezuela, in order to explore their structural and taxonomic implications. Fresh material sampled wild population was fixed in FAA and hand-sectioned or with a rotary microtome, following standardized protocols. Histochemical tests were carried out in some components. Obtained preparations were studied under a calibrated optical microscope; some variables were quantified by means of an eyepiece micrometer. The obtained results allowed the anatomical differentiation of the studied species and the two morphotypes. Most informative diagnostic variables identified include the thickening shape of the cells in the exodermis walls (transverse section), parenchyma cells with circular contours in the cortex, length of air spaces, the differentiation of passage cells in the endodermis, shared “V” and “Y” shaped xylem arches, the shape of phloem strands and scattered metaxylem vessels in the pith. Our results are also discussed in the context of other structural studies published on roots of different members of Arecaceae.

Targeted expression of the arsenate reductase HAC1 identifies cell type specificity of arsenic metabolism and transport in plant roots

High Arsenic Concentration 1 (HAC1), an Arabidopsis thaliana arsenate reductase, plays a key role in arsenate [As(V)] tolerance. Through conversion of As(V) to arsenite [As(III)], HAC1 enables As(III) export from roots, and restricts translocation of As(V) to shoots. To probe the ability of different root tissues to detoxify As(III) produced by HAC1, we generated A. thaliana lines expressing HAC1 in different cell types. We investigated the As(V) tolerance phenotypes: root growth, As(III) efflux, As translocation, and As chemical speciation. We showed that HAC1 can function in the outer tissues of the root (epidermis, cortex, and endodermis) to confer As(V) tolerance, As(III) efflux, and limit As accumulation in shoots. HAC1 is less effective in the stele at conferring As(V) tolerance phenotypes. The exception is HAC1 activity in the protoxylem, which we found to be sufficient to restrict As translocation, but not to confer As(V) tolerance. In conclusion, we describe cell type-specific functions of HAC1 that spatially separate the control of As(V) tolerance and As translocation. Further, we identify a key function of protoxylem cells in As(V) translocation, consistent with the model where endodermal passage cells, above protoxylem pericycle cells, form a ‘funnel’ loading nutrients and potentially toxic elements into the vasculature.

Study of Dosage-Dependent Effects of Cytostatic Drugs Using a Fibroblast Cell Culture of the Human Nasal Mucosa

Introduction Knowing a concentration at which cytostatic drugs are toxic for the nasal fibroblasts will enable the use cytostatic drugs in the clinical practice to prevent excessive cicatrization. Objective To determine the cytostatic concentrations of mitomycin С, doxorubicin, and 5-fluorouracil affecting nasal mucosa fibroblasts. Methods We obtained material during an endonasal dacryocystorhinostomy with the patient's informed consent. The cells were cultivated. Second- to fourth-passage cells were used in the experiments. The cells were stained for vimentin and cluster of differentiation 90 (CD90). An MTS test 3 (3-(4,5-dimethylthiazole-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium); cell viability test was performed. Results The cytostatic drugs have a toxic effect on cultivated fibroblasts of the nasal mucosa. This effect is dose-dependent. In terms of reducing the level of tissue fibrotisation in the nasal cavity, the most justified approach is to carry out an experimental study of the effect of mitomycin C, doxorubicin, and 5-fluorouracil at the concentrations of 0.25 mg/ml, 0.25 mg/ml, and 12.5 mg/ml respectively. Conclusion The authors argue that it is inappropriate to use these cytostatic drugs to conduct studies with the goal of analyzing their antifibrotic effect on the nasal mucosa at concentrations that are either lower or higher than the aforementioned ones.

Astrocyte senescence may drive alterations in GFAPα, CDKN2A p14ARF, and TAU3 transcript expression and contribute to cognitive decline

The accumulation of senescent cells in tissues is causally linked to the development of several age-related diseases; the removal of senescent glial cells in animal models prevents Tau accumulation and cognitive decline. Senescent cells can arise through several distinct mechanisms; one such mechanism is dysregulation of alternative splicing. In this study, we characterised the senescent cell phenotype in primary human astrocytes in terms of SA-β-Gal staining and SASP secretion, and then assessed splicing factor expression and candidate gene splicing patterns. Finally, we assessed associations between expression of dysregulated isoforms and premature cognitive decline in 197 samples from the InCHIANTI study of ageing, where expression was present in both blood and brain. We demonstrate here that senescent astrocytes secrete a modified SASP characterised by increased IL8, MMP3, MMP10, and TIMP2 but decreased IL10 levels. We identified significant changes in splicing factor expression for 10/20 splicing factors tested in senescent astrocytes compared with early passage cells, as well as dysregulation of isoform levels for 8/13 brain or senescence genes tested. Finally, associations were identified between peripheral blood GFAPα, TAU3, and CDKN2A (P14ARF) isoform levels and mild or severe cognitive decline over a 3–7-year period. Our data are suggestive that some of the features of cognitive decline may arise from dysregulated splicing of important genes in senescent brain support cells, and that defects in alternative splicing or splicing regulator expression deserve exploration as points of therapeutic intervention in the future.