Generation and characterization of human induced pluripotent stem cell line METUi001-A from a 25-year-old male patient with relapsing-remitting multiple sclerosis

© 2021Multiple sclerosis is a chronic disease characterized by inflammation, demyelination, and axonal damage in the central nervous system. Here, we established an induced pluripotent stem cell (iPSC) line METUi001-A from the peripheral blood mononuclear cells of a 25-year-old male individual with clinically diagnosed Relapsing-Remitting Multiple Sclerosis (RRMS) using the integration-free Sendai reprogramming method. We demonstrated that the iPSCs are free of exogenous Sendai reprogramming vectors, have a normal male karyotype, express pluripotency markers, and differentiate into the three germ layers. The iPSC line can serve as a valuable resource to generate cellular model systems to investigate molecular mechanisms underlying RRMS

Apoptotic Vascular Smooth Muscle Cell Depletion via BCL2 Family of Proteins in Human Ascending Aortic Aneurysm and Dissection

Cataloged from PDF version of article.Aims: This study investigates the expression patterns of BCL2 (B-cell CLL/lymphoma2) family of proteins and the extent of vascular smooth muscle cell (VSMC) apoptosis in thoracic aortic aneurysms (TAA), type-A aortic dissections (TAD), and nondilated ascending aortic samples. Methods: Aortic wall specimens were obtained from patients undergoing surgical repair for TAA (n = 24), TAD (n = 20), and normal aortic tissues from organ donors (n = 6). The expression pattern of BCL2, BCL2L1 (BCL2-like1), BAK1 (BCL2-antagonist/killer1), and BAX (BCL2-associated X protein) proteins was investigated by immunohistochemistry. Furthermore, colocalization of alpha smooth muscle actin (ACTA2) and caspase3 (CASP3) in aortic VSMCs was analyzed by double-immunofluorescence staining. Onset of DNA fragmentation was measured by TUNEL assay. Results: Apoptotic index was significantly increased in both TAD group (31.3 ± 17.2, P < 0.001) and TAA group (21.1 ± 12.7, P = 0.001) relative to control aortas (2.0 ± 1.2). Anti-CASP3 and ACTA2 double-immunostaining confirmed apoptosis in VSMCs in TAA and TAD groups but not in controls. Proapoptotic BAX expression was significantly elevated in VSMCs of TAA patients, compared with that of controls (OR = 20; P = 0.02; 95% CI, 16-250). In contrast, antiapoptotic BCL2L1 expression was higher in controls compared with that of TAA group (OR = 11.2; P = 0.049; 95% CI, 1.0-123.9). Furthermore, BAX/BCL2 ratio was significantly increased in both TAA (1.2 ± 0.7, P < 0.001) and TAD (0.6 ± 0.4, P = 0.05) groups relative to controls (0.2 ± 0.1, P < 0.001). Conclusions: Apoptotic VSMC depletion in human TAA/TAD is associated with disturbance of the balance between proapoptotic and antiapoptotic members of the BCL2 family proteins, which may have a role in the pathogenesis of vascular remodelling in aortic disease. In light of the future studies, targeting apoptotic pathways in TAA and TAD pathogenesis may provide therapeutic benefits to patients by slowing down the progression and even possibly preventing the TAD. © 2012 Blackwell Publishing Ltd

Participation of the Melanocortin-1 Receptor in the UV Control of Pigmentation

The cloning of the melanocortin-1 receptor (MC1R) gene from human melanocytes and the demonstration that these cells respond to the melanocortins α-melanocyte stimulating hormone (α-MSH) and adrenocorticotropic hormone (ACTH) with increased proliferation and melanogenesis have renewed the interest in investigation the physiological role of these hormones in regulating human pigmentation. α-Melanocyte stimulating hormone and ACTH are both synthesized in the human epidermis, and their synthesis is upregulated by exposure to ultraviolet radiation (UVR). Activation of the MC1R by ligand binding results in stimulation of cAMP formation, which is a principal mechanism for inducing melanogenesis. The increase in cAMP is required for the pigmentary response of human melanocytes to UVR, and for allowing them to overcome the UVR-induced G1 arrest. Treatment of human melanocytes with α-MSH increases eumelanin synthesis, an effect that is expected to enhance photoprotection of the skin. Population studies have revealed more than 20 allelic variants of the MC1R gene. Some of these variants are overexpressed in individuals with skin type I or II, red hair, and poor tanning ability. Future studies will aim at further exploration of the role of these variants in MC1R function, and in determining constitutive human pigmentation, the response to sun exposure, and possibly the susceptibility to skin cancer

Canonical Wnt signaling is antagonized by noncanonical Wnt5a in hepatocellular carcinoma cells

<p>Abstract</p> <p>Background</p> <p>β-catenin mutations that constitutively activate the canonical Wnt signaling have been observed in a subset of hepatocellular carcinomas (HCCs). These mutations are associated with chromosomal stability, low histological grade, low tumor invasion and better patient survival. We hypothesized that canonical Wnt signaling is selectively activated in well-differentiated, but repressed in poorly differentiated HCCs. To this aim, we characterized differentiation status of HCC cell lines and compared their expression status of Wnt pathway genes, and explored their activity of canonical Wnt signaling.</p> <p>Results</p> <p>We classified human HCC cell lines into "well-differentiated" and "poorly differentiated" subtypes, based on the expression of hepatocyte lineage, epithelial and mesenchymal markers. Poorly differentiated cell lines lost epithelial and hepatocyte lineage markers, and overexpressed mesenchymal markers. Also, they were highly motile and invasive. We compared the expression of 45 Wnt pathway genes between two subtypes. TCF1 and TCF4 factors, and LRP5 and LRP6 co-receptors were ubiquitously expressed. Likewise, six Frizzled receptors, and canonical Wnt3 ligand were expressed in both subtypes. In contrast, canonical ligand Wnt8b and noncanonical ligands Wnt4, Wnt5a, Wnt5b and Wnt7b were expressed selectively in well- and poorly differentiated cell lines, respectively. Canonical Wnt signaling activity, as tested by a TCF reporter assay was detected in 80% of well-differentiated, contrary to 14% of poorly differentiated cell lines. TCF activity generated by ectopic mutant β-catenin was weak in poorly differentiated SNU449 cell line, suggesting a repressive mechanism. We tested Wnt5a as a candidate antagonist. It strongly inhibited canonical Wnt signaling that is activated by mutant β-catenin in HCC cell lines.</p> <p>Conclusion</p> <p>Differential expression of Wnt ligands in HCC cells is associated with selective activation of canonical Wnt signaling in well-differentiated, and its repression in poorly differentiated cell lines. One potential mechanism of repression involved Wnt5a, acting as an antagonist of canonical Wnt signaling. Our observations support the hypothesis that Wnt pathway is selectively activated or repressed depending on differentiation status of HCC cells. We propose that canonical and noncanonical Wnt pathways have complementary roles in HCC, where the canonical signaling contributes to tumor initiation, and noncanonical signaling to tumor progression.</p

Graphene Oxide Nanosheets Interact and Interfere with SARS‐CoV‐2 Surface Proteins and Cell Receptors to Inhibit Infectivity

From Wiley via Jisc Publications RouterHistory: received 2021-03-13, pub-electronic 2021-05-14Article version: VoRPublication status: PublishedFunder: University of PaduaFunder: UKRI EPSRC; Grant(s): EP/P00119X/1Funder: Turkish Academy of Sciences (TUBA)Funder: Scientific and Technology Council of Turkey; Grant(s): 18AG020Funder: Türkiye Bilimler Akademisi; Id: http://dx.doi.org/10.13039/501100004412; Grant(s): GEBIP 2018Funder: Türkiye Bilimsel ve Teknolojik Araştirma Kurumu; Id: http://dx.doi.org/10.13039/501100004410; Grant(s): 18AG020Funder: Engineering and Physical Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000266; Grant(s): EP/P00119X/1Abstract: Nanotechnology can offer a number of options against coronavirus disease 2019 (COVID‐19) acting both extracellularly and intracellularly to the host cells. Here, the aim is to explore graphene oxide (GO), the most studied 2D nanomaterial in biomedical applications, as a nanoscale platform for interaction with SARS‐CoV‐2. Molecular docking analyses of GO sheets on interaction with three different structures: SARS‐CoV‐2 viral spike (open state – 6VYB or closed state – 6VXX), ACE2 (1R42), and the ACE2‐bound spike complex (6M0J) are performed. GO shows high affinity for the surface of all three structures (6M0J, 6VYB and 6VXX). When binding affinities and involved bonding types are compared, GO interacts more strongly with the spike or ACE2, compared to 6M0J. Infection experiments using infectious viral particles from four different clades as classified by Global Initiative on Sharing all Influenza Data (GISAID), are performed for validation purposes. Thin, biological‐grade GO nanoscale (few hundred nanometers in lateral dimension) sheets are able to significantly reduce copies for three different viral clades. This data has demonstrated that GO sheets have the capacity to interact with SARS‐CoV‐2 surface components and disrupt infectivity even in the presence of any mutations on the viral spike. GO nanosheets are proposed to be further explored as a nanoscale platform for development of antiviral strategies against COVID‐19

The Ability to Generate Senescent Progeny as a Mechanism Underlying Breast Cancer Cell Heterogeneity

Background Breast cancer is a remarkably heterogeneous disease. Luminal, basal-like, "normal-like", and ERBB2+ subgroups were identified and were shown to have different prognoses. The mechanisms underlying this heterogeneity are poorly understood. In our study, we explored the role of cellular differentiation and senescence as a potential cause of heterogeneity. Methodology/Principal Findings A panel of breast cancer cell lines, isogenic clones, and breast tumors were used. Based on their ability to generate senescent progeny under low-density clonogenic conditions, we classified breast cancer cell lines as senescent cell progenitor (SCP) and immortal cell progenitor (ICP) subtypes. All SCP cell lines expressed estrogen receptor (ER). Loss of ER expression combined with the accumulation of p21Cip1 correlated with senescence in these cell lines. p21Cip1 knockdown, estrogen-mediated ER activation or ectopic ER overexpression protected cells against senescence. In contrast, tamoxifen triggered a robust senescence response. As ER expression has been linked to luminal differentiation, we compared the differentiation status of SCP and ICP cell lines using stem/progenitor, luminal, and myoepithelial markers. The SCP cells produced CD24+ or ER+ luminal-like and ASMA+ myoepithelial-like progeny, in addition to CD44+ stem/progenitor-like cells. In contrast, ICP cell lines acted as differentiation-defective stem/progenitor cells. Some ICP cell lines generated only CD44+/CD24-/ER-/ASMA- progenitor/stem-like cells, and others also produced CD24+/ER- luminal-like, but not ASMA+ myoepithelial-like cells. Furthermore, gene expression profiles clustered SCP cell lines with luminal A and "normal-like" tumors, and ICP cell lines with luminal B and basal-like tumors. The ICP cells displayed higher tumorigenicity in immunodeficient mice. Conclusions/Significance Luminal A and "normal-like" breast cancer cell lines were able to generate luminal-like and myoepithelial-like progeny undergoing senescence arrest. In contrast, luminal B/basal-like cell lines acted as stem/progenitor cells with defective differentiation capacities. Our findings suggest that the malignancy of breast tumors is directly correlated with stem/progenitor phenotypes and poor differentiation potential. © 2010 Mumcuoglu et al

Generation and characterization of human induced pluripotent stem cell line METUi001-A from a 25-year-old male patient with relapsing-remitting multiple sclerosis

© 2021Multiple sclerosis is a chronic disease characterized by inflammation, demyelination, and axonal damage in the central nervous system. Here, we established an induced pluripotent stem cell (iPSC) line METUi001-A from the peripheral blood mononuclear cells of a 25-year-old male individual with clinically diagnosed Relapsing-Remitting Multiple Sclerosis (RRMS) using the integration-free Sendai reprogramming method. We demonstrated that the iPSCs are free of exogenous Sendai reprogramming vectors, have a normal male karyotype, express pluripotency markers, and differentiate into the three germ layers. The iPSC line can serve as a valuable resource to generate cellular model systems to investigate molecular mechanisms underlying RRMS

Preparation and characterization of poly(hydroxyethyl methacrylate-co -poly(ethyleneglycol-methacrylate)/hydroxypropyl-chitosan) hydrogel films: Adhesion of rat mesenchymal stem cells

This study examined the effects of the surface properties of the materials, such as the hydroxyl, methyl and amino groups, on rat bone marrow derived Mesenchymal Stem Cell (MSC) seeding. A series of hydrogels were prepared in film form using 2-hydroxyethyl methacrylate (pHEMA), poly(ethyleneglycol) methacrylate (PEG-MA), and/or hydroxypropyl-chitosan (HPC). The physicochemical properties of these hydrogel films, such as water content, functional groups, contact angle, surface energy and thermal properties were affected by the composition of the materials. The ability of the MSCs to form colonies, as well as their viability on these materials were also analyzed. The water content of the hydrogel films increased with increasing PEG-MA and HPC ratio in the hydrogel. Contact angle measurements of the surface of the hydrogel films demonstrated that all the materials gave rise to a significantly hydrophilic surface compared to pure pHEMA. The blood protein interactions and platelet adhesion were reduced significantly on the surface of the materials upon the incorporation of PEG-MA compared to the control pure pHEMA and vice versa for HPC. The ability of the MSCs to adhere and form colonies on these materials was also analyzed. The results showed that these materials are suitable candidates to isolate and expand MSCs. [Figure not available: see fulltext.] © 2011 The Polymer Society of Korea and Springer Netherlands

A new method for detecting pedicular wall perforation during pedicle screw insertion.

Study Design. Sensitivity, specificity, and predictive value analyses of a method that can be used to detect pedicular wall perforation during pedicle screw insertion were assessed