scholarly journals Minireview: Role of genetic changes of faciogenital dysplasia protein 1 in human disease

2016 ◽  
Vol 48 (7) ◽  
pp. 446-454 ◽  
Author(s):  
Nancy G. Pedigo ◽  
Danielle Van Delden ◽  
Laura Walters ◽  
Christopher L. Farrell
Keyword(s):  
Cell Adhesion ◽  
Embryonic Development ◽  
Rho Gtpase ◽  
Molecular Switch ◽  
Cellular Migration ◽  
Missense Mutations ◽  
Metastatic Tumors ◽  
Genetic Changes ◽  
Insertion And Deletion ◽  
Faciogenital Dysplasia

The FGD1 gene encodes for a guanine exchange factor (GEF) protein that specifically activates the Rho GTPase Cdc42. For cellular migration, Cdc42 is a key molecular switch that regulates cytoskeleton restructuring, gene transcription, cellular morphology, extension, and cell adhesion. In the past decade, germline mutations in the FGD1 gene have been associated with a rare X-linked disorder known as faciogenital dysplasia (FGDY). Malformations are consistent with a loss of cellular migration during embryonic development. Insertion and deletion mutations in FGD1 result in a frameshift causing inactivation of fgd1 protein. Since Cdc42 is a key molecular switch in cytoskeletal restructuring and cell adhesion, the loss of fgd1 is postulated to attenuate Cdc42-mediated cellular migration in embryonic development. In metastatic tumors, Cdc42 modulates migration and invasiveness. Fgd1 overexpression has been found in infiltrating and poorly differentiated breast and invasive prostate tumors. Amplification at Xp11.21, the FGD1 gene locus, has been reported in several cancers. Sequencing analyses in numerous types of cancer have found missense mutations in the FGD1 gene in metastatic tumors. FGDY and cancer studies suggest that the germline and somatic changes downregulate or upregulate the FGD1 gene playing a key role in the development of diseases.

scholarly journals What are the markers of aggressiveness in prolactinomas? Changes in cell biology, extracellular matrix components, angiogenesis and genetics

2007 ◽  
Vol 156 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Alper Gürlek ◽  
Niki Karavitaki ◽  
Olaf Ansorge ◽  
John A H Wass
Keyword(s):  
Extracellular Matrix ◽  
Cell Adhesion ◽  
Growth Factor ◽  
Molecular Mechanisms ◽  
Cellular Migration ◽  
Tumour Suppressor Genes ◽  
Suprasellar Region ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
E Cadherin

Prolactinoma is the most common pituitary tumour in adults. Macroprolactinomas, particularly in men, may occasionally exhibit a very aggressive clinical course as evidenced by progressive growth, invasion through bone into the sphenoid sinus, cavernous sinus, suprasellar region or the nasopharynx. Some may even progress to pituitary carcinoma with craniospinal or systemic metastases. Aggressive tumours have low cure rates despite appropriate medical and surgical treatment. The mechanisms underlying this aggressive biological behaviour have not yet been fully clarified. Recent immunohistochemical, molecular and genetic studies have provided some insight in this respect. Invasive prolactinomas may be associated with a high Ki-67/MIB-1 labelling index indicating increased cell proliferation, although this is not a universal finding. The AA polymorphism in the cyclin adenine (A)/guanine (G) gene is more frequently detected in invasive prolactinomas. Increased expression of the polysialylated neural cell adhesion molecule (NCAM) and reduced expression of the E-cadherin/catenin complex implies a contribution of altered cell-to-cell adhesion and cellular migration. Extracellular matrix components (ECM), matrix metalloproteinases (MMPs) and their inhibitors play important roles in the context of angiogenesis and invasion. The induction of fibroblast growth factor and vascular endothelial growth factor via oestrogen-induced overexpression of novel genes (PTTG, hst and Edpm5) enhance cell growth, proliferation and angiogenesis contributing to invasiveness in prolactinomas. Although mutations in proto-oncogenes like Ras are uncommon, loss of tumour suppressor genes at loci 11q13, 13q12–14, 10q and 1p seem to be associated with invasiveness. Of the described mechanisms, only reduced E-cadherin/catenin expression and overexpression of hst gene seem to be relatively specific markers for prolactinoma invasiveness compared with other pituitary adenomas. Further research is needed to clarify the molecular mechanisms behind the aggressive course of some prolactinomas to predict those with a potentially poor clinical outcome, and to devise treatments that will eventually enable the cure of these challenging tumours.

scholarly journals Hereditary spastic paraplegia SPG8 mutations impair CAV1-dependent, integrin-mediated cell adhesion

2020 ◽  
Vol 13 (613) ◽  
pp. eaau7500 ◽  
Author(s):  
Seongju Lee ◽  
Hyungsun Park ◽  
Peng-Peng Zhu ◽  
Soon-Young Jung ◽  
Craig Blackstone ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Hereditary Spastic Paraplegia ◽  
Cultured Cells ◽  
Protein Abundance ◽  
Missense Mutations ◽  
Spastic Paraplegia ◽  
Lysosomal Degradation ◽  
Actin Nucleation ◽  
Cellular Pathogenesis ◽  
Syndrome Protein

Mutations in WASHC5 (also known as KIAA0196) cause autosomal dominant hereditary spastic paraplegia (HSP) type SPG8. WASHC5, commonly called strumpellin, is a core component of the Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex that activates actin nucleation at endosomes. Although various other cellular roles for strumpellin have also been described, none account for how SPG8-associated mutations lead to HSP. Here, we identified protein interactors of the WASH complex by immunoprecipitation and mass spectrometry and assessed the functions of strumpellin in cultured cells using both overexpression and RNA interference along with cell-spreading assays to investigate cell adhesion. We uncovered a decrease in CAV1 protein abundance as well as endosomal fission defects resulting from pathogenic SPG8 mutations. CAV1, a key component of caveolae, interacted with strumpellin in cells, and strumpellin inhibited the lysosomal degradation of CAV1. SPG8-associated missense mutations in strumpellin did not rescue endosomal tubulation defects, reduction in CAV1 protein abundance, or integrin-mediated cell adhesion in strumpellin-deficient cells. Mechanistically, we demonstrated that the WASH complex maintained CAV1 and integrin protein amounts by inhibiting their lysosomal degradation through its endosomal actin nucleation activity. In addition, the interaction of strumpellin with CAV1 stimulated integrin recycling, thereby promoting cell adhesion. These findings provide a molecular link between WASHC5 mutations and impairment of CAV1- and integrin-mediated cell adhesion, providing insights into the cellular pathogenesis of SPG8.

scholarly journals Association of Missense Mutations in Epoxyalkane Coenzyme M Transferase with Adaptation of Mycobacterium sp. Strain JS623 to Growth on Vinyl Chloride

2010 ◽  
Vol 76 (11) ◽  
pp. 3413-3419 ◽  
Author(s):  
Yang Oh Jin ◽  
Samantha Cheung ◽  
Nicholas V. Coleman ◽  
Timothy E. Mattes
Keyword(s):  
Vinyl Chloride ◽  
Mycobacterium Smegmatis ◽  
Missense Mutations ◽  
Wild Type ◽  
Coenzyme M ◽  
Genetic Changes ◽  
Cell Extracts ◽  
Chlorinated Solvent ◽  
Groundwater Pollutant

ABSTRACT Vinyl chloride (VC) is a toxic groundwater pollutant associated with plastic manufacture and chlorinated solvent use. Aerobic bacteria that grow on VC as a carbon and energy source can evolve in the laboratory from bacteria that grow on ethene, but the genetic changes involved are unknown. We investigated VC adaptation in two variants (JS623-E and JS623-T) of the ethene-oxidizing Mycobacterium strain JS623. Missense mutations in the EtnE gene developed at two positions (W243 and R257) in cultures exposed to VC but not in cultures maintained on ethene. Epoxyalkane-coenzyme M transferase (EaCoMT) activities in cell extracts of JS623-E and JS623-T (150 and 645 nmol/min/mg protein, respectively) were higher than that of wild-type JS623 (74 nmol/min/mg protein), and in both variant cultures epoxyethane no longer accumulated during growth on ethene. The heterologous expression of two variant etnE alleles (W243G [etnE1] and R257L [etnE2]) from strain JS623 in Mycobacterium smegmatis showed that they had 42 to 59% higher activities than the wild type. Recombinant JS623 cultures containing mutant EtnE genes cloned in the vector pMV261 adapted to growth on VC more rapidly than the wild-type JS623 strain, with incubation times of 60 days (wild type), 1 day (pMVetnE1), and 35 days (pMVetnE2). The JS623(pMVetnE) culture did not adapt to VC after more than 60 days of incubation. Adaptation to VC in strain JS623 is consistently associated with two particular missense mutations in the etnE gene that lead to higher EaCoMT activity. This is the first report to pinpoint a genetic change associated with the transition from cometabolic to growth-linked VC oxidation in bacteria.

Defective LFA-1 Mediated T Cell Motility In Chronic Lymphocytic Leukemia Is Mediated by Defects In the Rho GTPase Signaling Pathway

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 914-914
Author(s):  
Alan G. Ramsay ◽  
Rachel Evans ◽  
Lena Svensson ◽  
Shahryar Kiaii ◽  
Nancy Hogg ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Migration ◽  
Cell Adhesion ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Motility ◽  
Healthy Donor ◽  
Rho Gtpase ◽  
Lymphocytic Leukemia ◽  
Donor T Cells

Abstract Abstract 914 T lymphocytes have an essential role in adaptive immunity and rely on tightly regulated signaling through integrin lymphocyte function-associated antigen (LFA)-1 to migrate into lymph nodes and interact with antigen-presenting cells. Malignant cells modify their immune microenvironment to prevent effective host anti-tumor responses, promote tumor progression, and suppress the therapeutic benefit of immunotherapy treatments. Here we assessed LFA-1-mediated cell migration of highly purified T cells from treatment naïve chronic lymphocytic leukemia (CLL) patients compared to age-matched healthy donor T cells using CXCL12 stimulation and immobilized ICAM-1, the principal integrin ligand. Video microscopy with motility tracking analysis identified that both CD4 and CD8 T cells from CLL patients (n=14) exhibited significantly reduced migration rates (P < .01) compared to healthy donor T cells (5.5 ± 0.3 (SEM) μm/min and 4.4 ± 0.2 μm/min compared to 8.2 ± 0.3 μm/min and 7.5 ± 0.3 μm/min respectively). We further identified that direct CLL cell contact, and not soluble factors alone, induced similar T cell motility dysfunction in previously healthy CD3 T cells. Primary co-culture of healthy donor T cells with CLL cells caused a significant decrease in the speed of migration on ICAM-1 compared to coculture with control healthy B cells (6.2 ± 0.3 μm/min versus 9.5 ± 0.6 μm/min) (n=9) (P < .05). Next we sought to repair this T cell defect in CLL using a clinically relevant agent. We identify that treatment of CLL patient T cells (n=9) with lenalidomide restores rapid LFA-1 mediated migration on ICAM-1. Ex vivo treatment of CLL T cells with lenalidomide (1μM for 24 hours) significantly increased the speed of T cell migration compared to untreated patient T cells (7 ± 0.4 μm/min versus 2.5 ± 0.7 μm/min) (P < .05) and the rescued T cell migratory function of lenalidomide exposed patient T cells was comparable to healthy donor T cells treated with or without drug. Interference reflection microscopy (IRM) examining the contact zone between migrating T cells and ICAM-1 identified a significant CLL patient T cell adhesion defect (P < .05) with reduced spreading area and strength of adhesive contacts (pixel density) compared to healthy donor T cells. IRM was further utilized with pharmacological inhibitors to demonstrate that exposure to lenalidomide rescued CLL T cell adhesion by acting on the Rho family GTPases that are dysregulated in cancer patient T cells. Lenalidomide significantly increased (P < .05) levels of active RhoA in CLL patient T cells compared to untreated cells. In addition, untreated CLL patient T cells adhering to ICAM-1 exhibited significantly reduced expression levels of phosphorylated myosin light chain (MLC) compared to healthy donor T cells (P < .05) and this defect was repaired following lenalidomide treatment. MLC is normally phosphorylated by MLC kinase at the T cell leading edge and by the RhoA target, ROCK at the trailing edge, and is an important downstream signaling molecule during LFA-1-mediated T cell motility. Further expression analysis identified that lenalidomide significantly increased (P < .01) ICAM-1-engaged high-affinity LFA-1 in CLL patient T cells to levels comparable to healthy donor T cells. Overall, our results show that T cells in CLL patients have dysfunctional tumor-induced cytoskeletal signaling via the Rho GTPase signaling pathway, and this is reversed by lenalidomide, rescuing dynamic LFA-1 mediated outside-in signalling and migration. Lenalidomide's immunomodulatory activity was highly cancer T cell specific: rescuing defective LFA-1 migration and signaling in CLL T cells, but with no detectable effects on healthy donor T cells. These findings provide important mechanistic insight into the action of lenalidomide, and highlight the potential clinical utility of immunomodulatory drugs to rescue normal immune function in cancer. Disclosures: Gribben: Roche: Consultancy; Celgene: Consultancy; GSK: Honoraria; Napp: Honoraria.

scholarly journals P2Y5 is a Gαi, Gα12/13G protein-coupled receptor activated by lysophosphatidic acid that reduces intestinal cell adhesion

2009 ◽  
Vol 297 (4) ◽  
pp. G641-G654 ◽  
Author(s):  
Mike Lee ◽  
Sungwon Choi ◽  
Gunnel Halldén ◽  
Sek Jin Yo ◽  
Denise Schichnes ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Lysophosphatidic Acid ◽  
Rho Gtpase ◽  
Growth Factor Receptor ◽  
Luciferase Reporter ◽  
Intestinal Cell ◽  
Rgs Domain ◽  
Epidermal Growth ◽  
G Protein Coupled ◽  
Serum Response

P2Y5 is a G protein-coupled receptor that binds and is activated by lysophosphatidic acid (LPA). We determined that P2Y5 transcript is expressed along the intestinal mucosa and investigated the intracellular pathways induced by P2Y5 activation, which could contribute to LPA effects on intestinal cell adhesion. P2Y5 heterologously expressed in CHO and small intestinal hBRIE 380i cells was activated by LPA resulting in an increase in intracellular calcium ([Ca2+]i) when the cells concurrently expressed GαΔ6qi5myr. P2Y5 activation also increased the phosphorylation of ERK1/2 that was sensitive to pertussis toxin. Together these indicate that P2Y5 activation by LPA induces an increase in [Ca2+]iand ERK1/2 phosphorylation through Gαi. We discovered that P2Y5 was activated by farnesyl pyrophosphate (FPP) without a detectable change in [Ca2+]i. The activation of P2Y5 by LPA or FPP induced the activity of a serum response element (SRE)-linked luciferase reporter that was inhibited by the RGS domain of p115RhoGEF, C3 exotoxin, and Y-27632, suggesting the involvement of Gα12/13, Rho GTPase, and ROCK, respectively. However, only LPA-mediated induction of SRE reporter activity was sensitive to inhibitors targeting p38 MAPK, PI3K, PLC, and PKC. In addition, only LPA transactivated the epidermal growth factor receptor, leading to an induction of ERK1/2 phosphorylation. These observations correlate with our subsequent finding that P2Y5 activation by LPA, and not FPP, reduced intestinal cell adhesion. This study elucidates a mechanism whereby LPA can act as a luminal and/or serosal cue to alter mucosal integrity.

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