scholarly journals Differentiation-dependent PTPIP51 Expression in Human Skeletal Muscle Cell Culture

2009 ◽  
Vol 57 (5) ◽  
pp. 425-435 ◽  
Author(s):  
Justus Barop ◽  
Heinrich Sauer ◽  
Klaus Steger ◽  
Monika Wimmer
Keyword(s):  
Tyrosine Phosphatase ◽  
Strong Association ◽  
Linear Increase ◽  
Interacting Protein ◽  
Human Skeletal Muscle Cell ◽  
Specific Proteins ◽  
Myosin Heavy Chain Protein ◽  
Human Muscle Cells

Protein tyrosine phosphatase-interacting protein 51 (PTPIP51) expression was analyzed in proliferating and differentiating human myogenic cells cultured in vitro. Satellite cell cultures derived from four different individuals were used in this study. To analyze the expression of PTPIP51, myoblasts were cultured under conditions promoting either proliferation or differentiation. In addition, further differentiation of already-differentiated myobtubes was inhibited by resubmitting the cells to conditions promoting proliferation. PTPIP51 protein and mRNA were investigated in samples taken at defined time intervals by immunostaining, immunoblotting, in situ hybridization, and PCR. Image analyses of fluorescence immuno-stainings were used to quantify PTPIP51 in cultured myoblasts and myotubes. Myoblasts grown in the presence of epidermal and fibroblast growth factors (EGF and FGF), both promoting proliferation, expressed PTPIP51 on a basic level. Differentiation to multinuclear myotubes displayed a linear increase in PTPIP51 expression. The rise in PTPIP51 protein was paralleled by an augmented expression of muscle-specific proteins, namely, sarcoplasmic reticulum Ca2+ ATPase and myosin heavy-chain protein, both linked to a progressive state of myotubal differentiation. This differentiation-induced increase in PTPIP51 was partly reversible by resubmission of differentiated myotubes to conditions boosting proliferation. The results clearly point toward a strong association between PTPIP51 expression and differentiation in human muscle cells. (J Histochem Cytochem 57:425–435, 2009)

scholarly journals Tyrosine Phosphorylation of Selected Secretory Carrier Membrane Proteins, SCAMP1 and SCAMP3, and Association with the EGF Receptor

1998 ◽  
Vol 9 (7) ◽  
pp. 1661-1674 ◽  
Author(s):  
Theodore T. Wu ◽  
J. David Castle
Keyword(s):  
Membrane Proteins ◽  
Egf Receptor ◽  
Tyrosine Phosphatase ◽  
Chinese Hamster ◽  
Tyrosine Residue ◽  
Cell Interior ◽  
Murine Fibroblasts ◽  
Secretory Carrier Membrane Proteins

Secretory carrier membrane proteins (SCAMPs) are ubiquitously expressed proteins of post-Golgi vesicles. In the presence of the tyrosine phosphatase inhibitor vanadate, or after overexpression in Chinese hamster ovary (CHO) cells, SCAMP1 and SCAMP3 are phosphorylated selectively on tyrosine residue(s). Phosphorylation is reversible after vanadate washout in situ or when isolated SCAMP3 is incubated with the recombinant tyrosine phosphatase PTP1B. Vanadate also causes the partial accumulation of SCAMP3, but not SCAMP1, in “patches” at or near the cell surface. A search for SCAMP kinase activities has shown that SCAMPs 1 and 3, but not SCAMP2, are tyrosine phosphorylated in EGF-stimulated murine fibroblasts overexpressing the EGF receptor (EGFR). EGF catalyzes the progressive phosphorylation of the SCAMPs up to 1 h poststimulation and may enhance colocalization of the EGFR and SCAMP3 within the cell interior. EGF also induces SCAMP–EGFR association, as detected by coimmunoprecipitation, and phosphorylation of SCAMP3 is stimulated by the EGFR in vitro. These results suggest that phosphorylation of SCAMPs, either directly or indirectly, may be functionally linked to the internalization/down-regulation of the EGFR.

scholarly journals SGTA associates with intracellular aggregates in neurodegenerative diseases.

2020 ◽  
Author(s):  
Shun Kubota ◽  
Hiroshi Doi ◽  
Shigeru Koyano ◽  
Kenichi Tanaka ◽  
Shingo Ikeda ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Molecular Mechanisms ◽  
In Vitro Study ◽  
Interacting Proteins ◽  
Interacting Protein ◽  
Cytoplasmic Inclusions ◽  
Specific Proteins ◽  
Intracellular Aggregates ◽  
Polyq Diseases

Abstract Intracellular aggregates are a common pathological hallmark of neurodegenerative diseases such as polyglutamine (polyQ) diseases, amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), and multiple system atrophy (MSA). Aggregates are mainly formed by aberrant disease-specific proteins and are accompanied by accumulation of other aggregate-interacting proteins. Although aggregate-interacting proteins have been considered to modulate the formation of aggregates and to be involved in molecular mechanisms of disease progression, the components of aggregate-interacting proteins remain unknown. In this study, we showed that small glutamine-rich tetratricopeptide repeat-containing protein alfa (SGTA) is an aggregate-interacting protein in neurodegenerative diseases. Immunohistochemistry showed that SGTA interacted with intracellular aggregates in Huntington disease (HD) cell models and neurons of HD model mice. We also revealed that SGTA colocalized with intracellular aggregates in postmortem brains of patients with polyQ diseases including spinocerebellar ataxia (SCA)1, SCA2, SCA3, and dentatorubral–pallidoluysian atrophy. In addition, SGTA colocalized with glial cytoplasmic inclusions in the brains of MSA patients, whereas no accumulation of SGTA was observed in neurons of PD and ALS patients. In vitro study showed that SGTA bound to polyQ aggregates through its C-terminal domain and SGTA overexpression reduced intracellular aggregates. These results suggest that SGTA may play a role in the formation of aggregates and may act as potential modifier of molecular pathological mechanisms of polyQ diseases and MSA.

scholarly journals BMP-2 Variants in Breast Epithelial to Mesenchymal Transition and Microcalcifications Origin

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1381 ◽  
Author(s):  
Manuel Scimeca ◽  
Raffaella Giocondo ◽  
Manuela Montanaro ◽  
Annarita Granaglia ◽  
Rita Bonfiglio ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Strong Association ◽  
Positive Association ◽  
Breast Cancers ◽  
Human Breast ◽  
Mesenchymal Transition ◽  
Breast Cells ◽  
E Cadherin

This study aims to investigate the possible different roles of the BMP-2 variants, cytoplasmic and nuclear variant, in both epithelial to mesenchymal transition and in microcalcifications origin in human breast cancers. To this end, the in situ expression of cytoplasmic and nuclear BMP-2 was associated with the expression of the main epithelial to mesenchymal transition biomarkers (e-cadherin and vimentin) and molecules involved in bone metabolisms (RUNX2, RANKL, SDF-1) by immunohistochemistry. In addition, the expression of cytoplasmic and nuclear BMP-2 was associated with the presence of microcalcifications. Our data showed a significant association among the number of cytoplasmic BMP-2-positive cells and the number of both vimentin (positive association) and e-cadherin (negative association) positive breast cells. Conversely, no associations were found concerning the nuclear BMP-2-positive breast cells. Surprisingly, the opposite result was obtained by analyzing the variants of BMP-2 and both the expression of RANKL and SDF-1 and the presence of microcalcifications. Specifically, the presence of microcalcifications was related to the expression of nuclear BMP-2 variant rather than the cytoplasmic one, as well as a strong association between the number of nuclear BMP-2 and the expression of the main breast osteoblast-like cells (BOLCs) biomarkers. To further corroborate these data, an in vitro experiment for demonstrating the co-expression of nBMP-2 and RANKL or vimentin or SDF-1 in breast cancer cells that acquire the capability to produce microcalcifications was developed. These investigations confirmed the association between the nBMP-2 expression and both RANKL and SDF-1. The data supports the idea that whilst cytoplasmic BMP-2 can be involved in epithelial to mesenchymal transition phenomenon, the nuclear variant is related to the essential mechanisms for the formation of breast microcalcifications. In conclusion, from these experimental and translational perspectives, the complexity of BMP-2 signaling will require a detailed understanding of the involvement of specific BMP-2 variants in breast cancers.

scholarly journals PTPN4 negatively regulates CrkI in human cell lines

2013 ◽  
Vol 18 (2) ◽  
Author(s):  
Juan Zhou ◽  
Bingbing Wan ◽  
Jingxuan Shan ◽  
Huili Shi ◽  
Yanhong Li ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tyrosine Phosphatase ◽  
Ectopic Expression ◽  
Receptor Protein ◽  
Interacting Protein ◽  
Regulate Cell Growth ◽  
Hep3b Cells ◽  
Two Hybrid ◽  
Proline Rich Region

AbstractPTPN4 is a widely expressed non-receptor protein tyrosine phosphatase. Although its overexpression inhibits cell growth, the proteins with which it interacts to regulate cell growth are unknown. In this study, we identified CrkI as a PTPN4-interacting protein using a yeast two-hybrid, and confirmed this interaction using in vitro GST pull-down and co-immunoprecipitation and co-localization assays. We further determined the interactional regions as the SH3 domain of CrkI and the proline-rich region between amino acids 462 and 468 of PTPN4. Notably, overexpression of PTPN4 inhibits CrkI-mediated proliferation and wound healing of HEK293T cells, while knockdown of PTPN4 by siRNA in Hep3B cells enhances CrkI-mediated cell growth and motility. Moreover, our data show that ectopic expression of PTPN4 reduces the phosphorylation level of CrkI in HEK293T cells. These findings suggest that PTPN4 negatively regulates cell proliferation and motility through dephosphorylation of CrkI.

scholarly journals Pharmacological modulation of mitochondrial calcium uniporter controls lung inflammation in cystic fibrosis

2020 ◽  
Vol 6 (19) ◽  
pp. eaax9093 ◽  
Author(s):  
Alessandro Rimessi ◽  
Chiara Pozzato ◽  
Lorenzo Carparelli ◽  
Alice Rossi ◽  
Serena Ranucci ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Endoplasmic Reticulum ◽  
Tyrosine Phosphatase ◽  
Mitochondrial Calcium ◽  
Inflammasome Activation ◽  
Interacting Protein ◽  
Mitochondrial Calcium Uniporter ◽  
Calcium Uniporter

Mitochondria physically associate with the endoplasmic reticulum to coordinate interorganelle calcium transfer and regulate fundamental cellular processes, including inflammation. Deregulated endoplasmic reticulum–mitochondria cross-talk can occur in cystic fibrosis, contributing to hyperinflammation and disease progression. We demonstrate that Pseudomonas aeruginosa infection increases endoplasmic reticulum–mitochondria associations in cystic fibrosis bronchial cells by stabilizing VAPB-PTPIP51 (vesicle-associated membrane protein–associated protein B–protein tyrosine phosphatase interacting protein 51) tethers, affecting autophagy. Impaired autophagy induced mitochondrial unfolding protein response and NLRP3 inflammasome activation, contributing to hyperinflammation. The mechanism by which VAPB-PTPIP51 tethers regulate autophagy in cystic fibrosis involves calcium transfer via mitochondrial calcium uniporter. Mitochondrial calcium uniporter inhibition rectified autophagy and alleviated the inflammatory response in vitro and in vivo, resulting in a valid therapeutic strategy for cystic fibrosis pulmonary disease.

scholarly journals Myomixer is expressed during embryonic and post-larval hyperplasia, muscle regeneration and fusion of myoblats in rainbow trout (Oncorhynchus mykiss)

2020 ◽  
Author(s):  
Miquel Perello-Amoros ◽  
Cécile Rallière ◽  
Joaquim Gutiérrez ◽  
Jean-Charles Gabillard
Keyword(s):  
Muscle Regeneration ◽  
White Muscle ◽  
Larval Growth ◽  
Muscle Growth ◽  
Gene Encoding ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Specific Proteins ◽  
Mature Fish

1.AbstractIn contrast to mice or zebrafish, trout exhibits post-larval muscle growth through hypertrophy and formation of new myofibers (hyperplasia). The muscle fibers are formed by the fusion of mononucleated cells (myoblasts) regulated by several muscle-specific proteins such as myomaker or myomixer. In this work, we identified a unique gene encoding a myomixer protein of 77 amino acids (aa) in the trout genome. Sequence analysis and phylogenetic tree, showed moderate conservation of the overall protein sequence across teleost fish (61% of aa identity between trout and zebrafish myomixer sequences). Nevertheless, the functionally essential motif, AxLyCxL is perfectly conserved in all studied sequences of vertebrates. Using in situ hybridization, we observed that myomixer was highly expressed in the embryonic myotome, particularly in the hyperplasic area. Moreover, myomixer remained readily expressed in white muscle of juvenile (1 and 20 g) although its expression decreased in mature fish. We also showed that myomixer is up-regulated during muscle regeneration and in vitro myoblasts fusion. Together, these data indicate that myomixer expression is consistently associated with the formation of new myofibers during somitogenesis, post-larval growth and muscle regeneration in trout.

scholarly journals SGTA associates with intracellular aggregates in neurodegenerative diseases

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shun Kubota ◽  
Hiroshi Doi ◽  
Shigeru Koyano ◽  
Kenichi Tanaka ◽  
Hiroyasu Komiya ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Molecular Mechanisms ◽  
In Vitro Study ◽  
Interacting Proteins ◽  
Interacting Protein ◽  
Cytoplasmic Inclusions ◽  
Specific Proteins ◽  
Intracellular Aggregates ◽  
Polyq Diseases

AbstractIntracellular aggregates are a common pathological hallmark of neurodegenerative diseases such as polyglutamine (polyQ) diseases, amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), and multiple system atrophy (MSA). Aggregates are mainly formed by aberrant disease-specific proteins and are accompanied by accumulation of other aggregate-interacting proteins. Although aggregate-interacting proteins have been considered to modulate the formation of aggregates and to be involved in molecular mechanisms of disease progression, the components of aggregate-interacting proteins remain unknown. In this study, we showed that small glutamine-rich tetratricopeptide repeat-containing protein alfa (SGTA) is an aggregate-interacting protein in neurodegenerative diseases. Immunohistochemistry showed that SGTA interacted with intracellular aggregates in Huntington disease (HD) cell models and neurons of HD model mice. We also revealed that SGTA colocalized with intracellular aggregates in postmortem brains of patients with polyQ diseases including spinocerebellar ataxia (SCA)1, SCA2, SCA3, and dentatorubral–pallidoluysian atrophy. In addition, SGTA colocalized with glial cytoplasmic inclusions in the brains of MSA patients, whereas no accumulation of SGTA was observed in neurons of PD and ALS patients. In vitro study showed that SGTA bound to polyQ aggregates through its C-terminal domain and SGTA overexpression reduced intracellular aggregates. These results suggest that SGTA may play a role in the formation of aggregates and may act as potential modifier of molecular pathological mechanisms of polyQ diseases and MSA.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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