scholarly journals Profilaggrin is a major epidermal calcium-binding protein.

1993 ◽  
Vol 13 (1) ◽  
pp. 613-625 ◽  
Author(s):  
N G Markova ◽  
L N Marekov ◽  
C C Chipev ◽  
S Q Gan ◽  
W W Idler ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Expression Patterns ◽  
Epidermal Cells ◽  
Epidermal Differentiation ◽  
Amino Terminus ◽  
Calcium Signal ◽  
Dependent Manner ◽  
Structural Protein ◽  
Rnase Protection

Profilaggrin is a major highly phosphorylated protein component of the keratohyalin granules of mammalian epidermis. It contains 10 to 12 tandemly repeated filaggrin units and is processed into the intermediate filament-associated protein filaggrin by specific dephosphorylation and proteolysis during terminal differentiation of the epidermal cells. Later, filaggrin itself is degraded to free amino acids that participate in maintenance of epidermal flexibility. The present paper describes the structural organization of the 5' region of the human profilaggrin gene as well as the amino terminus of the profilaggrin protein. The primary profilaggrin transcript consists of three exons and two introns. The first exon (exon I) is only 54 bp and is untranslated. The coding sequences are distributed between exon II (159 bp) and exon III, which contains the information for 10 to 12 filaggrin repeats (972 bp each) and the 3' noncoding sequences. A very large intron separates exons I and II. The combination of a very short exon I with an unusually long intron 1 makes the structure of the profilaggrin gene unique among the epidermally expressed genes investigated so far. Comparison of the expression patterns revealed by primer extension and RNase protection analysis of foreskin epidermal and cultured keratinocyte RNAs suggests that alternately spliced messages, which are different from profilaggrin mRNA, are transcribed from the profilaggrin gene system at earlier stages of epidermal differentiation. The amino terminus of profilaggrin exhibits a significant homology to the small calcium-binding S100-like proteins. It contains two alpha-helical regions, termed EF-hands, that bind calcium in vitro. This is the first example of functional calcium-binding domains fused to a structural protein. We suggest that in addition to its role in filament aggregation and the maintenance of epidermal flexibility, profilaggrin may play an important role in the differentiation of the epidermis by autoregulating its own processing in a calcium-dependent manner or by participating in the transduction of calcium signal in epidermal cells.

Profilaggrin is a major epidermal calcium-binding protein

1993 ◽  
Vol 13 (1) ◽  
pp. 613-625
Author(s):  
N G Markova ◽  
L N Marekov ◽  
C C Chipev ◽  
S Q Gan ◽  
W W Idler ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Expression Patterns ◽  
Epidermal Cells ◽  
Epidermal Differentiation ◽  
Amino Terminus ◽  
Calcium Signal ◽  
Dependent Manner ◽  
Structural Protein ◽  
Rnase Protection

Profilaggrin is a major highly phosphorylated protein component of the keratohyalin granules of mammalian epidermis. It contains 10 to 12 tandemly repeated filaggrin units and is processed into the intermediate filament-associated protein filaggrin by specific dephosphorylation and proteolysis during terminal differentiation of the epidermal cells. Later, filaggrin itself is degraded to free amino acids that participate in maintenance of epidermal flexibility. The present paper describes the structural organization of the 5' region of the human profilaggrin gene as well as the amino terminus of the profilaggrin protein. The primary profilaggrin transcript consists of three exons and two introns. The first exon (exon I) is only 54 bp and is untranslated. The coding sequences are distributed between exon II (159 bp) and exon III, which contains the information for 10 to 12 filaggrin repeats (972 bp each) and the 3' noncoding sequences. A very large intron separates exons I and II. The combination of a very short exon I with an unusually long intron 1 makes the structure of the profilaggrin gene unique among the epidermally expressed genes investigated so far. Comparison of the expression patterns revealed by primer extension and RNase protection analysis of foreskin epidermal and cultured keratinocyte RNAs suggests that alternately spliced messages, which are different from profilaggrin mRNA, are transcribed from the profilaggrin gene system at earlier stages of epidermal differentiation. The amino terminus of profilaggrin exhibits a significant homology to the small calcium-binding S100-like proteins. It contains two alpha-helical regions, termed EF-hands, that bind calcium in vitro. This is the first example of functional calcium-binding domains fused to a structural protein. We suggest that in addition to its role in filament aggregation and the maintenance of epidermal flexibility, profilaggrin may play an important role in the differentiation of the epidermis by autoregulating its own processing in a calcium-dependent manner or by participating in the transduction of calcium signal in epidermal cells.

scholarly journals Calprotectin and the Initiation and Progression of Head and Neck Cancer

2018 ◽  
Vol 97 (6) ◽  
pp. 674-682 ◽  
Author(s):  
P.P. Argyris ◽  
Z.M. Slama ◽  
K.F. Ross ◽  
A. Khammanivong ◽  
M.C. Herzberg
Keyword(s):  
Head And Neck ◽  
Calcium Binding ◽  
Gene Networks ◽  
Tumor Formation ◽  
Carcinoma Cells ◽  
Epidermal Differentiation ◽  
Matrix Metalloproteinase 2 ◽  
Dependent Manner ◽  
Cellular Development

Calprotectin (S100A8/A9), a heterodimeric complex of calcium-binding proteins S100A8 and S100A9, is encoded by genes mapping to the chromosomal locus 1q21.3 of the epidermal differentiation complex. Whereas extracellular calprotectin shows proinflammatory and antimicrobial properties by signaling through RAGE and TLR4, intracytoplasmic S100A8/A9 appears to be important for cellular development, maintenance, and survival. S100A8/A9 is constitutively expressed in myeloid cells and the stratified mucosal epithelia lining the oropharyngeal and genitourinary mucosae. While upregulated in adenocarcinomas and other cancers, calprotectin mRNA and protein levels decline in head and neck squamous cell carcinoma (HNSCC). S100A8/A9 is also lost during head and neck preneoplasia (dysplasia). Calprotectin decrease does not correlate with the clinical stage (TNM) of HNSCC. When expressed in carcinoma cells, S100A8/A9 downregulates matrix metalloproteinase 2 expression and inhibits invasion and migration in vitro. S100A8/A9 regulates cell cycle progression and decelerates cancer cell proliferation by arresting at the G2/M checkpoint in a protein phosphatase 2α–dependent manner. In HNSCC, S100A8 and S100A9 coregulate with gene networks controlling cellular development and differentiation, cell-to-cell signaling, and cell morphology, while S100A8/A9 appears to downregulate expression of invasion- and tumorigenesis-associated genes. Indeed, tumor formation capacity is attenuated in S100A8/A9-expressing carcinoma cells in vivo. Hence, intracellular calprotectin appears to function as a tumor suppressor in head and neck carcinogenesis. When compared with S100A8/A9-low HNSCC based on analysis of TCGA, S100A8/A9-high HNSCC shows significant upregulation of apoptosis-related genes, including multiple caspases. Accordingly, S100A8/A9 facilitates DNA damage responses in HNSCC, promotes apoptotic cell death, and confers sensitivity to cisplatin and X-radiation in vitro. In the tumor milieu, loss of S100A8/A9 strongly associates with poor squamous differentiation and higher tumor grading, EGFR upregulation, increased DNA methylation, and, finally, poorer overall survival for patients with HNSCC. Hence, intracellular calprotectin shows a multifaceted protective role against the development of HNSCC.

scholarly journals Mislocalization of CDK11/PITSLRE, a regulator of the G2/M phase of the cell cycle, in Alzheimer disease

2011 ◽  
Vol 16 (3) ◽  
Author(s):  
Vladan Bajić ◽  
Bo Su ◽  
Hyoung-Gon Lee ◽  
Wataru Kudo ◽  
Sandra Siedlak ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Alzheimer Disease ◽  
Expression Patterns ◽  
Vital Role ◽  
Dependent Manner ◽  
Entry Site ◽  
Internal Ribosome Entry ◽  
Cellular Processes ◽  
M Phase

AbstractPost-mitotic neurons are typically terminally differentiated and in a quiescent status. However, in Alzheimer disease (AD), many neurons display ectopic re-expression of cell cycle-related proteins. Cyclin-dependent kinase 11 (CDK11) mRNA produces a 110-kDa protein (CDK11p110) throughout the cell cycle, a 58-kDa protein (CDK11p58) that is specifically translated from an internal ribosome entry site and expressed only in the G2/M phase of the cell cycle, and a 46-kDa protein (CDK11p46) that is considered to be apoptosis specific. CDK11 is required for sister chromatid cohesion and the completion of mitosis. In this study, we found that the expression patterns of CDK11 vary such that cytoplasmic CDK11 is increased in AD cellular processes, compared to a pronounced nuclear expression pattern in most controls. We also investigated the effect of amyloid precursor protein (APP) on CDK11 expression in vitro by using M17 cells overexpressing wild-type APP and APP Swedish mutant phenotype and found increased CDK11 expression compared to empty vector. In addition, amyloid-β25–35 resulted in increased CDK11 in M17 cells. These data suggest that CDK11 may play a vital role in cell cycle re-entry in AD neurons in an APP-dependent manner, thus presenting an intriguing novel function of the APP signaling pathway in AD.

scholarly journals The Class II Phosphoinositide 3-Kinase C2β Is Not Essential for Epidermal Differentiation

2005 ◽  
Vol 25 (24) ◽  
pp. 11122-11130 ◽  
Author(s):  
Kazutoshi Harada ◽  
Amy B. Truong ◽  
Ti Cai ◽  
Paul A. Khavari
Keyword(s):  
Class Ii ◽  
Epidermal Cells ◽  
Epidermal Differentiation ◽  
Class I ◽  
Differentiation Markers ◽  
Cellular Processes ◽  
Targeted Gene Deletion ◽  
Epidermal Growth ◽  
Phosphoinositide 3 Kinase

ABSTRACT Phosphoinositide 3-kinases (PI3Ks) regulate an array of cellular processes and are comprised of three classes. Class I PI3Ks include the well-studied agonist-sensitive p110 isoforms; however, the functions of class II and III PI3Ks are less well characterized. Of the three class II PI3Ks, C2α and C2β are widely expressed in many tissues, including the epidermis, while C2γ is confined to the liver. In contrast to the class I PI3K p110α, which is expressed throughout the epidermis, C2β was found to be localized in suprabasal cells, suggesting a potential role for C2β in epidermal differentiation. Overexpressing C2β in epidermal cells in vitro induced differentiation markers. To study a role for C2β in tissue, we generated transgenic mice overexpressing C2β in both suprabasal and basal epidermal layers. These mice lacked epidermal abnormalities. Mice deficient in C2β were then generated by targeted gene deletion. C2β knockout mice were viable and fertile and displayed normal epidermal growth, differentiation, barrier function, and wound healing. To exclude compensation by C2α, RNA interference was then used to knock down both C2α and C2β in epidermal cells simultaneously. Induction of differentiation markers was unaffected in the absence of C2α and C2β. These findings indicate that class II PI3Ks are not essential for epidermal differentiation.

scholarly journals Regulatory Role of PopN and Its Interacting Partners in Type III Secretion of Pseudomonas aeruginosa

2007 ◽  
Vol 189 (7) ◽  
pp. 2599-2609 ◽  
Author(s):  
Hongjing Yang ◽  
Zhiying Shan ◽  
Jaewha Kim ◽  
Weihui Wu ◽  
Wei Lian ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Protein Interactions ◽  
Type Iii Secretion ◽  
Calcium Binding ◽  
High Capacity ◽  
Calcium Signal ◽  
Dependent Manner ◽  
Protein Protein Interactions ◽  
Type Iii

ABSTRACT The type III secretion system (T3SS) of Pseudomonas aeruginosa plays a significant role in pathogenesis. We have previously identified type III secretion factor (TSF), which is required for effective secretion of the type III effector molecules, in addition to the low calcium signal. TSF includes many low-affinity high-capacity calcium binding proteins, such as serum albumin and casein. A search for the TSF binding targets on the bacterial outer membrane resulted in identification of PopN, a component of the T3SS that is readily detectable on the bacterial cell surface. PopN specifically interacts with Pcr1, and both popN and pcr1 mutants have a constitutive type III secretion phenotype, suggesting that the two proteins form a complex that functions as a T3SS repressor. Further analysis of the popN operon genes resulted in identification of protein-protein interactions between Pcr1 and Pcr4 and between Pcr4 and Pcr3, as well as between PopN and Pcr2 in the presence of PscB. Unlike popN and pcr1 mutants, pcr3 and pcr4 mutants are totally defective in type III secretion, while a pcr2 mutant exhibits reduced type III secretion. Interestingly, PopN, Pcr1, Pcr2, and Pcr4 are all secreted in a type III secretion machinery-dependent manner, while Pcr3 is not. These findings imply that these components have important regulatory roles in controlling type III secretion.

Characterization of the mouse metal-regulatory-element-binding proteins, metal element protein-1 and metal regulatory transcription factor-1

2001 ◽  
Vol 353 (3) ◽  
pp. 591-601 ◽  
Author(s):  
Olivier LAROCHELLE ◽  
Gale STEWART ◽  
Pierre MOFFATT ◽  
Véronique TREMBLAY ◽  
Carl SÉGUIN
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Binding Activity ◽  
Dependent Manner ◽  
Rnase Protection ◽  
Dna Binding Activity ◽  
Cell Extracts ◽  
Metal Element ◽  
Transcription Factor 1

Metal activation of metallothionein gene transcription depends mainly on the presence of regulatory DNA sequences termed metal-regulatory elements (MREs) and involves MRE-binding transcription factor-1 (MTF-1) interacting with the MREs in a Zn2+-dependent manner. We previously identified and characterized a nuclear protein, termed metal element protein-1 (MEP-1), specifically binding with high affinity to MRE elements. The precise relationship between MTF-1 and MEP-1 was unclear, and to determine whether MEP-1 and MTF-1 were distinct protein species, we performed DNA binding analyses to characterize the binding properties of both proteins. Electrophoretic mobility-shift assays showed that MTF-1, produced in COS cells, produces a slower-migrating band compared with that obtained with purified MEP-1. Using an anti-MTF-1 antibody, we showed that both the MTF-1–MRE and the MEP-1–MRE complexes are supershifted by an anti-MTF-1 antibody, thus demonstrating that MEP-1 is antigenically related to MTF-1. RNase protection analyses carried out with RNA prepared from different tissues and cell lines failed to reveal the presence of MTF-1 splicing variants. This indicates that MEP-1 may be a proteolytic fragment of MTF-1. MTF-1 DNA-binding activity was rapidly activated in vivo by Zn2+ ions but not by Cd2+, UV irradiation or PMA, and occurred on ice as well as at 21°C. In control and Zn2+-treated cell extracts, DNA-binding activity was not enhanced in vitro following the addition of exogenous Zn2+ or a preincubation at 37°C. However, recombinant MTF-1 produced in vitro required Zn2+ activation for DNA binding. Interestingly, treatment of nuclear extracts with calf intestine phosphatase completely abrogated MTF-1 DNA-binding activity, thus suggesting that phosphorylation is involved in the regulation of MTF-1 activity.

Putative imprinted gene expression in uniparental bovine embryo models

2008 ◽  
Vol 20 (5) ◽  
pp. 589 ◽  
Author(s):  
Nancy T. D' Cruz ◽  
Katrina J. Wilson ◽  
Melissa A. Cooney ◽  
R. Tayfur Tecirlioglu ◽  
Irina Lagutina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
Monoallelic Expression ◽  
Cell Physiology ◽  
Imprinted Genes ◽  
Bovine Embryo ◽  
Dependent Manner ◽  
Abnormal Growth

Altered patterns of gene expression and the imprinted status of genes have a profound effect on cell physiology and can markedly alter embryonic and fetal development. Failure to maintain correct imprinting patterns can lead to abnormal growth and behavioural problems, or to early pregnancy loss. Recently, it has been reported that the Igf2R and Grb10 genes are biallelically expressed in sheep blastocysts, but monoallelically expressed at Day 21 of development. The present study investigated the imprinting status of 17 genes in in vivo, parthenogenetic and androgenetic bovine blastocysts in order to determine the prevalence of this unique phenomenon. Specifically, the putatively imprinted genes Ata3, Impact, L3Mbtl, Magel2, Mkrn3, Peg3, Snrpn, Ube3a and Zac1 were investigated for the first time in bovine in vitro fertilised embryos. Ata3 was the only gene not detected. The results of the present study revealed that all genes, except Xist, failed to display monoallelic expression patterns in bovine embryos and support recent results reported for ovine embryos. Collectively, the data suggest that monoallelic expression may not be required for most imprinted genes during preimplantation development, especially in ruminants. The research also suggests that monoallelic expression of genes may develop in a gene- and time-dependent manner.

scholarly journals B7-H4 Expression is Upregulated by PKCδ Activation and Contributes to PKCδ-Induced Cell Mobility in Colorectal Cancer

2021 ◽  
Author(s):  
Bin Zhou ◽  
Youwei Lu ◽  
Zhiming Zhao ◽  
Tongguo Shi ◽  
Hongya Wu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Expression Patterns ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Colorectal Tumour ◽  
Protein Levels ◽  
Cell Mobility ◽  
Unknown Protein ◽  
Poor Differentiation

Abstract Background B7-H4 is overexpressed in colorectal cancer (CRC) and plays important roles in tumour growth and immunosuppression. However, the exact mechanism that regulates B7-H4 expression remains largely unknown. Protein kinase δ (PKCδ) plays a significant role in a range of cancers, including CRC. Here, we investigated whether PKCδ regulates the expression of B7-H4 in CRC.Methods By using immunohistochemical and immunofluorescence (IF) staining, we analysed the expression of B7-H4 and phospho-PKCδ (p-PKCδ) in 225 colorectal tumour samples, and the clinical significance of these expression patterns was determined. In vitro experiments were performed with the CRC cell lines HCT116 and SW620 to detect the effect of PKCδ activation on B7-H4 expression.Results B7-H4 expression was significantly correlated with p-PKCδ expression (r=0.378, P<0.001) in tumour tissues. The co-expression of p-PKCδ and B7-H4 was significantly associ­ated with moderate/poor differentiation (P=0.024), lymph node metastasis (P=0.001) and an advanced Dukes’ stage (P=0.002). Western blot analysis showed that TPA increased B7-H4 levels in a concentration-dependent manner and rottlerin also abrogated TPA-induced B7-H4 enhancement. The expression of B7-H4 and p-STAT3 were significantly reduced by PKCδ-specific siRNA. Moreover, STAT3 inhibitor cryptotanshinone significantly decreased B7-H4 protein levels in HCT116 cells. Knockdown of B7-H4 or PKCδ expression suppressed cell migration and mobility.Conclusion B7-H4 expression was significantly correlated with p-PKCδ expression in CRC samples. B7-H4 expression was upregulated by STAT3 activation via PKCδ and played roles in PKCδ-induced cancer cell mobility and metastasis.

scholarly journals Synthetic Hydroxyapatite Inhibits Bisphosphonate Toxicity to the Oral Mucosa In Vitro

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2086 ◽  
Author(s):  
George Bullock ◽  
Cheryl Miller ◽  
Alasdair McKechnie ◽  
Vanessa Hearnden
Keyword(s):  
Oral Mucosa ◽  
Metabolic Activity ◽  
Calcium Binding ◽  
Soft Tissues ◽  
Pamidronic Acid ◽  
Dependent Manner ◽  
Porous Hydroxyapatite ◽  
Socket Preservation ◽  
Oral Cells

Medication-related osteonecrosis of the jaw (MRONJ) is a side effect of bisphosphonate therapy, characterised by exposed necrotic bone. The soft tissues of the oral mucosa no longer provide a protective barrier and MRONJ patients experience pain, infections and difficulties eating. We hypothesised that hydroxyapatite (Ca5(PO4)3(OH)) could reduce bisphosphonate concentrations and protect the oral mucosa by exploiting bisphosphonate’s calcium binding affinity. The effect of zoledronic acid (ZA) and pamidronic acid (PA) on the metabolism of oral fibroblasts, oral keratinocytes and three-dimensional oral mucosa models was investigated and then repeated in the presence of hydroxyapatite granules. Without hydroxyapatite, ZA and PA significantly reduced the metabolic activity of oral cells in a dose-dependent manner. Both drugs reduced epithelial thickness and 30 µM ZA resulted in loss of the epithelium. Hydroxyapatite granules had a protective effect on oral cells, with metabolic activity retained. Oral mucosa models retained their multi-layered epithelium when treated with ZA in the presence of hydroxyapatite granules and metabolic activity was comparable to controls. These results demonstrate hydroxyapatite granules protected oral soft tissues from damage caused by bisphosphonate exposure. Porous hydroxyapatite granules are currently used for socket preservation and this data suggests their potential to prevent MRONJ in at-risk patients.

scholarly journals Pharmacological Inhibition of Class IIA HDACs by LMK-235 in Pancreatic Neuroendocrine Tumor Cells

2018 ◽  
Vol 19 (10) ◽  
pp. 3128 ◽  
Author(s):  
Julia Wanek ◽  
Martin Gaisberger ◽  
Marlena Beyreis ◽  
Christian Mayr ◽  
Katharina Helm ◽  
...  
Keyword(s):  
Cell Viability ◽  
Histone Deacetylases ◽  
Expression Patterns ◽  
Somatostatin Receptor ◽  
Annexin V ◽  
Pancreatic Neuroendocrine Tumor ◽  
Dependent Manner ◽  
Ki 67 ◽  
Phosphohistone H3

Histone deacetylases (HDACs) play a key role in epigenetic mechanisms in health and disease and their dysfunction is implied in several cancer entities. Analysis of expression patterns in pancreatic neuroendocrine tumors (pNETs) indicated HDAC5 to be a potential target for future therapies. As a first step towards a possible treatment, the aim of this study was to evaluate the in vitro cellular and molecular effects of HDAC5 inhibition in pNET cells. Two pNET cell lines, BON-1 and QGP-1, were incubated with different concentrations of the selective class IIA HDAC inhibitor, LMK-235. Effects on cell viability were determined using the resazurin-assay, the caspase-assay, and Annexin-V staining. Western Blot and immunofluorescence microscopy were performed to assess the effects on HDAC5 functionality. LMK-235 lowered overall cell viability by inducing apoptosis in a dose- and time-dependent manner. Furthermore, acetylation of histone-H3 increased with higher LMK-235 concentrations, indicating functional inhibition of HDAC4/5. Immunocytochemical analysis showed that proliferative activity (phosphohistone H3 and Ki-67) decreased at highest concentrations of LMK-235 while chromogranin and somatostatin receptor 2 (SSTR2) expression increased in a dose-dependent manner. HDAC5 expression was found to be largely unaffected by LMK-235. These findings indicate LMK-235 to be a potential therapeutic approach for the development of an effective and selective pNET treatment.

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