hPSC gene editing for cardiac disease therapy

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. However, the lack of human cardiomyocytes with proper genetic backgrounds limits the study of disease mechanisms. Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have significantly advanced the study of these conditions. Moreover, hPSC-CMs made it easy to study CVDs using genome-editing techniques. This article discusses the applications of these techniques in hPSC for studying CVDs. Recently, several genome-editing systems have been used to modify hPSCs, including zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeat-associated protein 9 (CRISPR/Cas9). We focused on the recent advancement of genome editing in hPSCs, which dramatically improved the efficiency of the cell-based mechanism study and therapy for cardiac diseases.

Antimicrobial and Biochemical Properties of Linum usitatissimum the Flax Seeds and Syzygium aromaticum

Introduction: The current research was performed to evaluate antimicrobial, anti-fungal and biochemical properties of Linum usitatissimum (flax seeds) and Syzygium aromaticum (clove). Flaxseeds is one of dietary sources containing phenolics, named lignans. Syzygium aromaticum ordinarily called clove is generally considered second important flavor in world and is broadly developed in North Maluku Islands in Indonesia. Glycosides, saponins, flavonoids, steroids, tannins, alkaloids, terpenes, and other phytochemical constituents have been shown to have pharmacological actions in different activities. Syzygium aromaticum (clove) and Linum usitatissimum (flax) have unique pharmacological effects and have been utilized for food safety.Materials and Methods: In this study, ethanolic, methanolic and aqueous extracts of Linum usitatissimum and Syzygium aromaticum were evaluated against the 3 bacterial strains and 2 contagious fungal strains viz. A. niger and F. solani.Results: Among the bacterial strains i.e., E. coli, P. syringae and B. subtilis, antimicrobial action was noted by Syzygium aromaticum against E. coli, methanolic and aqueous extract of Linum usitatissimum and ethanolic extract of S. aromaticum showed antimicrobial action against the P. syringae and B. subtilis. Best antimicrobial action was observed by the ethanolic extract of the L. usitatissimum and methanolic and aqueous extract of S. aromaticum. Regarding parasitic strains of A. niger and F. solani, 3 extracts of L. usitatissimum showed satisfactory results against A. niger strain and 2 extracts (ethanolic and methanolic) of S. aromaticum against F. solani strain, whereas aqueous extracts of both the plants had no effect against F. solani strain. The phytochemical screening showed presence of terpenoids, tannins, flavonoids, saponins and cardiovascular glycosides in both plants.Conclusion: Flaxseed and clove extracts were found potent antimicrobial agents.

c-KIT-ERK1/2 signaling activated ELK1 and upregulated carcinoembryonic antigen expression to promote colorectal cancer progression

Carcinoembryonic antigen (CEA) is highly expressed in embryo and colorectal cancer (CRC) and has been widely used as a marker for CRC. Emerging evidence has demonstrated that elevated CEA levels promote CRC progression. However, the mechanism of the increased CEA expression in patients with primary and recurrent CRC is still an open question. In this study, we showed that c‐KIT, ELK1, and CEA were hyperexpressed in patients with CRC, especially patients with recurrent disease. From bioinformatics analysis, we picked ELK1 as a candidate transcription factor (TF) for CEA; the binding site of ELK1 within the CEA promoter was confirmed by chromatin immunoprecipitation and dual luciferase reporter assays. Overexpression of ELK1 increased CEA expression in vitro, while knockdown of ELK1 decreased CEA. Upregulated ELK1 promoted the adhesion, migration, and invasion of CRC cells, however knockdown of CEA blocked the activities of ELK1‐overexpressed CRC cells. Furthermore, we explored the role of c‐KIT‐ERK1/2 signaling in activation of ELK1. Blocking c‐KIT signaling using Imatinib or ISCK03 reduced p‐ELK1 expression and consequently decreased CEA levels in CRC cells, as did blocking the ERK1/2 pathway by U0126. Compared with wild type littermates, the c‐kit loss‐of‐functional Wads^m/m mice showed lowered c‐KIT, ELK1, and CEA expression. In conclusion, our study revealed that ELK1, which was activated by c‐KIT‐ERK1/2 signaling, was a key TF for CEA expression. Blocking ELK1 or its upstream signaling could be an alternative way to decelerate CRC progression. Besides being a biomarker for CRC, CEA could be used for guiding targeted therapy.

Degree of neutrophil chemotaxis is dependent upon the chemoattractant and barrier

Stimulated neutrophil migration across lung endothelial and epithelial barriers is important in lung inflammatory processes. To better understand the interaction between chemoattractants, neutrophils, and endothelium and epithelium, we compared the ability of leukotriene B4 (LTB4), formylmethionylleucylphenylalanine (FMLP), and platelet-activating factor (PAF) to induce human neutrophil migration across 3-microns-pore filters alone and human umbilical vein endothelial (HUVE) cells and two different epithelial cell types, Madin-Darby canine kidney (MDCK) cells and human lung A549 cells, cultured in monolayers on these filters. LTB4, FMLP, and PAF induced neutrophil migration through naked filters, endothelial cells, and epithelial cells in a dose-related fashion. At optimal chemoattractant doses, LTB4, FMLP, and PAF induced relatively equivalent neutrophil migration through filters and endothelial and epithelial monolayers. However, the doses at which optimal neutrophil migration was observed to occur as well as the degree of neutrophil migration through the three barriers varied depending upon the chemoattractant. Based on dose-response experiments, the relative rank order of potency for the three chemoattractants was: LTB4 = FMLP greater than PAF for filter alone barrier; LTB4 greater than FMLP greater than PAF for HUVE cell barrier; and FMLP greater than LTB4 greater than PAF for MDCK and A549 epithelial cell barriers. Our data suggest that neutrophil chemotactic and subsequent lung inflammatory responses are interrelatedly influenced by both the quantity and type of chemoattractant present and the barrier through which the neutrophil must migrate.

Effects of various barriers on platelet-activating factor-induced neutrophil chemotaxis

Platelet-activating factor (PAF)-induced neutrophil migration across endothelial and epithelial barriers is an important event in inflammation. We compared the effects of PAF on human neutrophil migration through filters alone, and human umbilical vein endothelial and Madin-Darby canine kidney epithelial cells cultured on these filters. We found that the amount of PAF-induced neutrophil migration was barrier dependent. At low PAF concentrations, neutrophil migration through filters exceeded migration measured through either cellular barrier. As PAF concentrations increased to greater than or equal to 1 mumol/L, neutrophil migration through human umbilical vein endothelial cells often equaled or exceeded migration measured through filters alone. In contrast, significant neutrophil migration through Madin-Darby canine kidney cells was not observed until PAF concentrations exceeded 50 mumol/L. Thus, the intensity of PAF-induced neutrophil inflammatory processes is, in part, dependent on the barrier through which the neutrophils must migrate.

Comparison of leukotriene B4-induced neutrophil migration through different cellular barriers

Migration of neutrophils across epithelial or endothelial barriers in response to chemotactic stimuli occurs in inflammation and host defense. Leukotriene B4 (LTB4) may be synthesized by and certainly induces chemotaxis of neutrophils. To better understand the interaction between LTB4, neutrophils, and endothelium and epithelium, we compared the effects of LTB4 on human peripheral blood neutrophil migration through filters alone and on human umbilical vein endothelial (HUVE) cells and three different epithelial cell types, Madin-Darby canine kidney (MDCK) cells, human colon carcinoma (T84) cells, and rat type II alveolar cells, cultured on these filters. Significant LTB4-stimulated neutrophil migration occurred at the lowest (1 nM) dose and in the shortest period of time (15 min) across endothelial cells vs. all three epithelial cell types, and interestingly, vs. filters alone. Dose-response experiments (1-100 nM) indicated that at equimolar LTB4 concentrations neutrophil migration across endothelium was two- to threefold greater than that observed across filters alone and the three epithelial barriers. At higher LTB4 concentrations (100 nM), the degree of neutrophil migration through the three epithelial barriers was equivalent to that observed for filters alone. Overall, the data indicate that the various cellular barriers play an active role in inflammatory processes by regulating the transmigration of neutrophils in response to certain inflammatory chemotactic stimuli.

Soluble proteins from Schistosoma mansoni and japonicum: a comparative biochemical and immunological analysis

1. Soluble proteins were recovered from male Schistosoma mansoni after homogenization in Tris-HCl buffer containing 0.6 M KCl and 1.0% Triton X-100 followed by preparative electrophoresis on SDS-gel. 2. Polyclonal antibodies produced in mice against the soluble fraction were used in comparative analysis of S. mansoni and S. japonicum using immunoblots and immunoprecipitation of in vitro translated polypeptides. 3. Small molecular weight polypeptide (20-22 kdalton), identified by infected mouse serum (IMS) on immunoblots, was predominant in females and was not cross-reactive with heterologous IMS. 4. A 41-43 kdalton polypeptide which appeared as a doublet on immunoblots performed with polyclonal antiserum 4M, was predominant in males of both species although the polypeptides of S. mansoni showed slower electrophoretic mobility, and therefore the larger size (43 kdalton), than that of S. japonicum. 5. Comparison of fluorograms of the immunoprecipitates of in vitro translated polypeptides indicated that IMS of S. mansoni precipitated two, 30 and 94 kdalton, polypeptides while the IMS of S. japonicum identified at 72 kdalton polypeptide. Antisera 1M, 2M and 4M also showed similarities and differences in polypeptides of in vitro translation products of the two species of Schistosoma.

Actin and intermediate-sized filaments of the spines and cytoskeleton of Schistosoma mansoni

The organization of spines and filaments in whole worms and cytoskeletal fractions of adult Schistosoma mansoni was investigated. The ultrastructure of the spine revealed a closely packed filamentous organization of 3.5- to 5.6-nm elements and electron-lucent areas. Spines were surrounded at the base by electron-dense bodies and membrane invaginations, and covered at the tip by the syncytial surface membrane. Filaments, 7.5-11.1 nm in diameter, were closely associated with the base of the spines, between muscles, near mitochondria or nuclei, and in spaces of the subtegument. Cytoskeletal fractions prepared by homogenizing adults in Tris-HCl buffer, containing 0.6 M KCl and 1.0% Triton X-100, represented 19%-25% and 32%-38% of wet weight of males and females, respectively. The fractions contained nuclei, spines, 8 to 11 nm filaments, myofibrils, and granules. Vitellaria and egg shells were abundant in fractions from females. Six polypeptides with estimated molecular weights of 130, 96, 84, 78, 74 and 43 kdaltons were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as the major components of the cytoskeleton. Monoclonal antibody to chicken actin (MAA) was localized predominantly in surface spines and tubercles of adult schistosomes by the indirect immunofluorescence test, while immune serum from infected mice reacted less specifically with the tegument. A 43-kdalton polypeptide with electrophoretic mobility identical to that of vertebrate actin, identified in cytoskeletal and tegumental fractions of adult worms, reacted positively with MAA on immunoblotting.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino acid and lipid composition of refringent granules from the ameboid sperm of Ascaris suum (Nematoda)

Transformation of the spermatozoon of Ascaris suum from a spheroidal to an ameboid cell is associated with the formation of a motile pseudopodium and coalescence of the intracellular refringent granules. The pseudopodia of the ameboid spermatozoa contain filaments organized into dense patches, bundles, web-like or lace-like networks, as observed by electron microscopy. The morphology and chemistry of the refringent granules were investigated in subcellular fractions enriched for these structures. Isolated refringent granules were heterogeneous in size measuring from 0.5 X 0.6 to 2.3 X 3.5 microns. Each granule is surrounded by a 110 A thick layer. During fusion, the surfaces of the refringent granules form small extensions resembling micropodia. The process of fusion occurs at many sites on a given granule and simultaneous fusion of several granules was commonly observed. Amino acid analyses of the refringent granule proteins (RGP's) indicated: they are rich in aspartic acid or asparagine (48%), leucine (10%), serine (19%) and aromatic amino acids (11%). Gas-liquid chromatographic analyses of alditol acetate derivatives of monosaccharides released by mild acid hydrolysis showed the predominant sugars to be glucose (7.3 micrograms/mg protein), galactose (9.2 micrograms/mg) and N-acetylglucosamine (5.5 micrograms/mg). Lipid analyses indicated a complex mixture of glycerides, ascarosides and waxes, together with a major component that resembled free fatty acid in mobility on TLC.

Identification of surface antigens of Sarcocystis muris (Coccidia)

Zoites of Sarcocystis muris were recovered from the skeletal muscles of infected mice by trypsin digestion. Extracts of zoites prepared by freeze-thaw, Triton X-100 (0.1%), or a combination of the two treatments contained antigenic components. Testing of these antigens by agar gel diffusion and immunoelectrophoresis against sera from infected mice showed one major precipitin band. SDS-polyacrylamide-gel electrophoresis (SDS-PAGE) of the extracts revealed at least eight detectable polypeptides ranging in molecular weight from 10,000 to 220,000. The antigenic components of the extract were identified by labeling the parasite surface with [125I] and precipitation of the [125I]-labeled antigens with immune sera. Analysis of the immunoprecipitates by SDS-PAGE and autoradiography revealed three antigens with molecular weights of 27,500, 43,000 and 90,000. The smallest of these was the predominant antigen as suggested by labeling intensity.

Comparison of iodinated antigens of metastatic and non-metastatic mammary adenocarcinoma cells

The surface and detergent-soluble proteins of metastatic (TMT-081) and nonmetastatic (MT-100) mammary adenocarcinoma cells were labeled using [125I]-lactoperoxidase. The iodinated proteins were analyzed by SDS-gel electrophoresis and autoradiography. The results revealed seven iodinated surface polypeptides in metastatic cells with molecular weights of 150,000, 130,000, 110,000, 78,000, 67,000, 40,000 and 22,000. The nonmetastatic cell surface revealed eight iodinated polypeptides with molecular weights of 175,000, 150,000, 130,000, 120,000, 110,000, 67,000, 40,000, and 24,000. The small molecular weight polypeptides, 22,000-24,000, of both metastatic and nonmetastatic cells were the most intensely labeled and appeared as a major surface component. Iodination of the detergent-soluble proteins in tumor extracts results in the labeling of five polypeptides (175,000, 67,000, 44,000, 29,000, 22,000 MW) of metastatic tumor and six polypeptides (175,000, 78,000, 67,000, 40,000, 35,000, 22,000 MW) of nonmetastatic tumor. Immunoprecipitation analyses indicate that the iodinated tumor polypeptides are antigenic to a xenogenic host. The 175,000 MW surface polypeptide of nonmetastatic and the 40,000 MW polypeptide of metastatic cells were not detected in the immunoprecipitates. The results of immunoprecipitation suggest that the small molecular weight (22,000-24,000) polypeptides are the predominant antigens of both tumor cells.

Ultrastructure and fatty acid composition of fatty acid-modified Morris 7777 hepatoma cells

Morris 7777 hepatoma cells, maintained in culture for 5 days in Lewis medium supplemented with 0.1 to 0.35 mM cis-unsaturated fatty acid of the oleic (number of carbon atoms: number of double bonds, 18:1), linoleic (18:2), or arachidonic (20:4) type, were compared to similarly maintained, unsupplemented cells as to ultrastructure and fatty acid composition. The cells of unsupplemented cultures were distinguished by their spherical shape, multilobated nuclei, large nucleoli, and distribution of chromatin. Cellular extensions in the form of pseudopodia and filopodia along with junctional complexes and structures resembling bile canaliculi were evident. The cytoplasmic matrix and cellular organelles appeared normal in morphology. The ultrastructure of fatty acid-supplemented cells differed from unsupplemented hepatoma cells in cell size, location of the nucleus, abundance of endoplasmic reticulum, accumulation of lipid droplets, mitochondrial abnormalities, redistribution of cytoplasmic fibrils, and plasmalemmal extensions. Supplemented cells contained lipid droplets varying in number from a optimum of six to a maximum of greater than 70. The size of these lipid droplets varied from 0.57 +/- 0.34 (S.D.) micrometers for oleic, 1.22 +/- 0.67 micrometers for linoleic, and 0.91 +/- 0.46 micrometers for arachidonic acid-supplemented cells. Variation in the ultrastructure of supplemented cells was also evident. Cytoplasmic vesiculation appeared more frequently and was more prominent in the linoleic acid-supplemented cells. Alterations in the number of surface specializations and nuclear morphology were more pronounced in the arachidonic acid-supplemented cells. Occasional swelling, loss of matrix density, and dilated cristae were evident in mitochondria of oleic acid-supplemented cells. The neutral and phospholipid fractions of arachidonic acid-supplemented cells differed from the unsupplemented cells in the concentrations of 14:0, 15:0, 16:0, 16:1, 17:0, 18:0, 18:1, 18:2, 20:1, 20:3, 20:4, 22:5, and 22:6 fatty acids. The most significant change was detected in the higher level, 26- or 8-fold, of fatty acids 20:3 omega 6 and 22:6 in the phospholipid fraction of arachidonic acid-supplemented cells.

Subcellular fractions and the refringent granules of the spermatozoa of Ascaris suum (Nematoda)

Six subcellular fractions were isolated by differential centrifugation of the homogenate of spermatozoa of Ascaris suum. The cellular constituents of pelleted fractions, as identified by electron microscopy, were membranes and membranous organelles (fraction A1), microsomal (A2), cytoplasmic (A3), large refringent granules (B1), small refringent granules (B2) and a detergent-soluble fraction (B3). Polypeptide analysis of SDS-PAGE showed that the 18,400-dalton band, one of the major spermatozoan proteins, is detectable in all of the fractions. However, the cytoplasmic (A1) and refringent-granule (B1) fractions contained the highest level. The isolated refringent granules consisted of 2-6% lipid while the nonlipid fraction formed an insoluble matrix with a fibrillar network morphology. This fibrillar matrix contained three polypeptides of small molecular weight (7,000-14,000) in addition to the 18,400-dalton polypeptide. These small polypeptides (7,000--14,000 MW) are detectable only in fractions of the refringent granules and are therefore called the refringent-granule proteins (RGP). These RGP are sensitive to tryptic hydrolysis and have solubility properties similar to the protein, ascaridine.

Surface receptors: are they involved in transformation of spermatozoa of Ascaris?

Exposure of the spheroidal spermatozoa of Ascaris suum to an extract of the male accessory gland causes their transformation into ameboid cells. We have investigated the mechanism of this transformation, also termed activation, by labeling the proteins of accessory gland extracts with fluorescein isothiocyanate (FITC) or [125I], followed by qualitative localization of the sperm activating substances (SAS) and quantitative measurements of [125I]-SAS binding. Fluorescent patches of FITC-conjugated SAS were localized at the spermatozoan surface and were concentrated primarily at the posterior region. Few fluorescent patches were detectable in the region of the newly formed pseudopodia following transformation. Although spermatozoan transformation occurs within 2-5 min after exposure to SAS, the fluorescent patches became more distinct after a minimum of 8 min and reached maximum density at 15-30 min. Spermatozoa activated with [125I]-SAS became radioactively labeled in direct proportion to the amount of available [125I]-SAS until a saturation level was reached. SDS-polyacrylamide gel electrophoresis combined with autoradiography indicated that the cells bind two SAS components, of small (9,000 MW) and large (56,000 MW) sizes. These same two components were also detectable in a membrane fraction, obtained by differential centrifugation, of the spermatozoa after incubation with [125I]-SAS. binding of the two SAS components was not inhibited by preincubation of the spermatozoa with trypsin or Concanavalin A; however, the 56,000 MW component of SAS was not detectable in autoradiograms of spermatozoa incubated with periodic acid (1.6-10 mM) treated SAS. Such cells also failed to transform into ameboid spermatozoa. These results indicate that the two components of SAS that bind to the spermatozoan surface are possibly responsible for inducing the cell transformations associated with activation.