Functional role of TRPC proteins in vivo: lessons from TRPC-deficient mouse models

2004 ◽  
Vol 322 (4) ◽  
pp. 1352-1358 ◽  
Author(s):  
M. Freichel ◽  
R. Vennekens ◽  
J. Olausson ◽  
M. Hoffmann ◽  
C. Müller ◽  
...  
Keyword(s):  
Mouse Models ◽  
Functional Role ◽  
Deficient Mouse ◽  
Trpc Proteins

scholarly journals Pathophysiological Role of Autophagy: Lesson from Autophagy-Deficient Mouse Models

2011 ◽  
Vol 60 (4) ◽  
pp. 329-345 ◽  
Author(s):  
Yoshinobu ICHIMURA ◽  
Masaaki KOMATSU
Keyword(s):  
Mouse Models ◽  
Deficient Mouse ◽  
Pathophysiological Role

scholarly journals Insights on the Functional Role of Beta-Glucans in Fungal Immunity Using Receptor-Deficient Mouse Models

2021 ◽  
Vol 22 (9) ◽  
pp. 4778
Author(s):  
Mark Joseph Maranan Desamero ◽  
Soo-Hyun Chung ◽  
Shigeru Kakuta
Keyword(s):  
Mouse Models ◽  
Deficient Mouse ◽  
Beta Glucan ◽  
Downstream Signaling ◽  
Beta Glucans ◽  
Fungal Immunity ◽  
Anti Fungal ◽  
Susceptibility And Resistance ◽  
Deficient Mice

Understanding the host anti-fungal immunity induced by beta-glucan has been one of the most challenging conundrums in the field of biomedical research. During the last couple of decades, insights on the role of beta-glucan in fungal disease progression, susceptibility, and resistance have been greatly augmented through the utility of various beta-glucan cognate receptor-deficient mouse models. Analysis of dectin-1 knockout mice has clarified the downstream signaling pathways and adaptive effector responses triggered by beta-glucan in anti-fungal immunity. On the other hand, assessment of CR3-deficient mice has elucidated the compelling action of beta-glucans in neutrophil-mediated fungal clearance, and the investigation of EphA2-deficient mice has highlighted its novel involvement in host sensing and defense to oral mucosal fungal infection. Based on these accounts, this review focuses on the recent discoveries made by these gene-targeted mice in beta-glucan research with particular emphasis on the multifaceted aspects of fungal immunity.

scholarly journals WNT-5A regulates TGF-β-related activities in liver fibrosis

2017 ◽  
Vol 312 (3) ◽  
pp. G219-G227 ◽  
Author(s):  
Leonie Beljaars ◽  
Sara Daliri ◽  
Christa Dijkhuizen ◽  
Klaas Poelstra ◽  
Reinoud Gosens
Keyword(s):  
Liver Fibrosis ◽  
Functional Role ◽  
Collagen Type ◽  
Collagen Type I ◽  
Matrix Proteins ◽  
Type I ◽  
Human Livers

WNT-5A is a secreted growth factor that belongs to the noncanonical members of the Wingless-related MMTV-integration family. Previous studies pointed to a connection between WNT-5A and the fibrogenic factor TGF-β warranting further studies into the functional role of WNT-5A in liver fibrosis. Therefore, we studied WNT-5A expressions in mouse and human fibrotic livers and examined the relation between WNT-5A and various fibrosis-associated growth factors, cytokines, and extracellular matrix proteins. WNT-5A gene and protein expressions were significantly increased in fibrotic mouse and human livers compared with healthy livers. Regression or therapeutic intervention in mice resulted in decreased hepatic WNT-5A levels paralleled by lower collagen levels. Immunohistochemical analysis showed WNT-5A staining in fibrotic septa colocalizing with desmin staining indicating WNT-5A expression in myofibroblasts. In vitro studies confirmed WNT-5A expression in this cell type and showed that TGF-β significantly enhanced WNT-5A expression in contrast to PDGF-BB and proinflammatory cytokines IL-1β and TNF-α. Additionally, TGF-β induces the expression of the WNT receptors FZD2 and FZD8. After silencing of WNT-5A, reduced levels of collagen type I, vimentin, and fibronectin in TGF-β-stimulated myofibroblasts were measured compared with nonsilencing siRNA-treated controls. Interestingly, the antifibrotic cytokine IFNγ suppressed WNT-5A in vitro and in vivo. IFNγ-treated fibrotic mice showed significantly less WNT-5A expression compared with untreated fibrotic mice. In conclusion, WNT-5A paralleled collagen I levels in fibrotic mouse and human livers. WNT-5A expression in myofibroblasts is induced by the profibrotic factor TGF-β and plays an important role in TGF-β-induced regulation of fibrotic matrix proteins, whereas its expression can be reversed upon treatment, both in vitro and in vivo. NEW & NOTEWORTHY This study describes the localization and functional role of WNT-5A in human and mouse fibrotic livers. Hepatic WNT-5A expression parallels collagen type I expression. In vivo and in vitro, the myofibroblasts were identified as the key hepatic cells producing WNT-5A. WNT-5A is under control of TGF-β and its activities are primarily profibrotic.

scholarly journals Cathepsin G-dependent platelet stimulation by activated polymorphonuclear leukocytes and its inhibition by antiproteinases: role of P-selectin-mediated cell-cell adhesion

Blood ◽  
1993 ◽  
Vol 81 (11) ◽  
pp. 2947-2957 ◽  
Author(s):  
V Evangelista ◽  
P Piccardoni ◽  
JG White ◽  
G de Gaetano ◽  
C Cerletti
Keyword(s):  
Functional Role ◽  
Polymorphonuclear Leukocytes ◽  
Platelet Adhesion ◽  
Inhibitory Effect ◽  
Serotonin Release ◽  
Cathepsin G ◽  
Inhibitory Antibody ◽  
Neuraminidase Treatment

Human PMN stimulated by fMLP are able to activate coincubated, autologous platelets. Cathepsin G, a neutral serine protease stored in the azurophilic granules of PMN, is the major platelet activator in this system. We previously proposed that shear-induced close PMN- platelet contact creates the conditions for which cathepsin G activity on platelets is protected against antiproteinases. The aim of this study was to investigate the adhesive mechanisms, possibly creating between PMN and platelet membranes the microenvironment in which cathepsin G, discharged from stimulated PMN onto adherent platelets, is protected against antiproteinases. Microscopic examination showed that under conditions of high shear, 71.3% +/- 6.1% of PMN were associated to platelets forming small clumps. This percentage decreased to 10% +/- 2% and 13% +/- 4%, respectively, in the presence of an inhibitory antibody to P-selectin or 20 mmol/L mannose-1-phosphate and to 10.8% +/- 3.7% when cells were not stirred. Similarly, PMN pretreatment with neuraminidase abolished PMN binding to platelets. These results indicate that P-selectin mediates PMN-platelet adhesion occurring before PMN stimulation. Prevention of PMN-platelet contact significantly potentiated the inhibitory effect of alpha 1-protease inhibitor on subsequent cathepsin G-induced platelet serotonin release. Because anti-P-selectin antibody, mannose-1-phosphate, and neuraminidase treatment of PMN did not modify PMN-induced platelet activation in the absence of antiproteinases, it is suggested that P- selectin-mediated PMN-platelet adhesion results in the formation of a sequestered microenvironment between cell membranes, in which higher amounts of antiproteinases are required to prevent the activity of released cathepsin G. These data add a new functional role to P- selectin-mediated PMN-platelet adhesion that could be important in vivo because of the presence of antiproteinases in plasma.

scholarly journals Immunoproteasomes as a novel antiviral mechanism in rhinovirus-infected airways

2018 ◽  
Vol 132 (15) ◽  
pp. 1711-1723 ◽  
Author(s):  
Kris Genelyn Dimasuay ◽  
Amelia Sanchez ◽  
Niccolette Schaefer ◽  
Jorge Polanco ◽  
Deborah A. Ferrington ◽  
...  
Keyword(s):  
Viral Load ◽  
Antigen Processing ◽  
Lower Airway ◽  
Chronic Obstructive ◽  
Deficient Mouse ◽  
Obstructive Pulmonary Disease ◽  
Tracheal Epithelial Cells ◽  
And Function

Rhinovirus (RV) infection is involved in acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD). RV primarily infects upper and lower airway epithelium. Immunoproteasomes (IP) are proteolytic machineries with multiple functions including the regulation of MHC class I antigen processing during viral infection. However, the role of IP in RV infection has not been explored. We sought to investigate the expression and function of IP during airway RV infection. Primary human tracheobronchial epithelial (HTBE) cells were cultured at air–liquid interface (ALI) and treated with RV16, RV1B, or interferon (IFN)-λ in the absence or presence of an IP inhibitor (ONX-0914). IP gene (i.e. LMP2) deficient mouse tracheal epithelial cells (mTECs) were cultured for the mechanistic studies. LMP2-deficient mouse model was used to define the in vivo role of IP in RV infection. IP subunits LMP2 and LMP7, antiviral genes MX1 and OAS1 and viral load were measured. Both RV16 and RV1B significantly increased the expression of LMP2 and LMP7 mRNA and proteins, and IFN-λ mRNA in HTBE cells. ONX-0914 down-regulated MX1 and OAS1, and increased RV16 load in HTBE cells. LMP2-deficient mTECs showed a significant increase in RV1B load compared with the wild-type (WT) cells. LMP2-deficient (compared with WT) mice increased viral load and neutrophils in bronchoalveolar lavage (BAL) fluid after 24 h of RV1B infection. Mechanistically, IFN-λ induction by RV infection contributed to LMP2 and LMP7 up-regulation in HTBE cells. Our data suggest that IP are induced during airway RV infection, which in turn may serve as an antiviral and anti-inflammatory mechanism.

scholarly journals Increased Human Wildtype Tau Attenuates Axonal Transport Deficits Caused by Loss of App in Mouse Models

2010 ◽  
Vol 4 ◽  
pp. MRI.S5237 ◽  
Author(s):  
Karen D.B. Smith ◽  
Erica Peethumnongsin ◽  
Han Lin ◽  
Hui Zheng ◽  
Robia G. Pautler
Keyword(s):  
Synaptic Plasticity ◽  
Axonal Transport ◽  
Mouse Models ◽  
Knockout Mice ◽  
Early Age ◽  
Axonal Elongation ◽  
Protein Tau ◽  
Manganese Enhanced Mri

Amyloid precursor protein (APP) is implicated in axonal elongation, synaptic plasticity, and axonal transport. However, the role of APP on axonal transport in conjunction with the microtubule associated protein tau continues to be debated. Here we measured in vivo axonal transport in APP knockout mice with Manganese Enhanced MRI (MEMRI) to determine whether APP is necessary for maintaining normal axonal transport. We also tested how overexpression and mutations of tau affect axonal transport in the presence or absence of APP. In vivo axonal transport reduced significantly in the absence of functional APP. Overexpression of human wildtype tau maintained normal axonal transport and resulted in a transient compensation of axonal transport deficits in the absence of APP. Mutant R406Wtau in combination with the absence of APP compounded axonal transport deficits and these deficits persisted with age. These results indicate that APP is necessary for axonal transport, and overexpression of human wildtype tau can compensate for the absence of APP at an early age.

Contribution of R domain phosphoserines to the function of CFTR studied in Fischer rat thyroid epithelia

2000 ◽  
Vol 279 (5) ◽  
pp. L835-L841 ◽  
Author(s):  
Olafur Baldursson ◽  
Herbert A. Berger ◽  
Michael J. Welsh
Keyword(s):  
Functional Role ◽  
Transmembrane Conductance Regulator ◽  
Regulatory Domain ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
Dependent Protein ◽  
Rat Thyroid ◽  
Cystic Fibrosis Transmembrane

The regulatory domain of cystic fibrosis transmembrane conductance regulator (CFTR) regulates channel activity when several serines are phosphorylated by cAMP-dependent protein kinase. To further define the functional role of individual phosphoserines, we studied CFTR containing previously studied and new serine to alanine mutations. We expressed these constructs in Fischer rat thyroid epithelia and measured transepithelial Cl− current. Mutation of four in vivo phosphorylation sites, Ser660, Ser737, Ser795, and Ser813 (S-Quad-A), substantially decreased cAMP-stimulated current, suggesting that these four sites account for most of the phosphorylation-dependent response. Mutation of either Ser660 or Ser813 alone significantly decreased current, indicating that these residues play a key role in phosphorylation-dependent stimulation. However, neither Ser660 nor Ser813 alone increased current to wild-type levels; both residues were required. Changing Ser737 to alanine increased current above wild-type levels, suggesting that phosphorylation of Ser737 may inhibit current in wild-type CFTR. These data help define the functional role of regulatory domain phosphoserines and suggest interactions between individual phosphoserines.

scholarly journals Integrin α10, a Novel Therapeutic Target in Glioblastoma, Regulates Cell Migration, Proliferation, and Survival

Cancers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 587 ◽  
Author(s):  
Matilda Munksgaard Thorén ◽  
Katarzyna Chmielarska Masoumi ◽  
Cecilia Krona ◽  
Xiaoli Huang ◽  
Soumi Kundu ◽  
...  
Keyword(s):  
Cell Death ◽  
Therapeutic Target ◽  
Functional Role ◽  
Treatment Strategies ◽  
Antibody Drug Conjugate ◽  
Potential Therapeutic Target ◽  
Sphere Formation

New, effective treatment strategies for glioblastomas (GBMs), the most malignant and invasive brain tumors in adults, are highly needed. In this study, we investigated the potential of integrin α10β1 as a therapeutic target in GBMs. Expression levels and the role of integrin α10β1 were studied in patient-derived GBM tissues and cell lines. The effect of an antibody–drug conjugate (ADC), an integrin α10 antibody conjugated to saporin, on GBM cells and in a xenograft mouse model was studied. We found that integrin α10β1 was strongly expressed in both GBM tissues and cells, whereas morphologically unaffected brain tissues showed only minor expression. Partial or no overlap was seen with integrins α3, α6, and α7, known to be expressed in GBM. Further analysis of a subpopulation of GBM cells selected for high integrin α10 expression demonstrated increased proliferation and sphere formation. Additionally, siRNA-mediated knockdown of integrin α10 in GBM cells led to decreased migration and increased cell death. Furthermore, the ADC reduced viability and sphere formation of GBM cells and induced cell death both in vitro and in vivo. Our results demonstrate that integrin α10β1 has a functional role in GBM cells and is a novel, potential therapeutic target for the treatment of GBM.

Identifying the Functional Role of Martinotti Cells in Cortical Sensory Processing

2009 ◽  
Vol 102 (1) ◽  
pp. 9-11 ◽  
Author(s):  
James C. H. Cottam
Keyword(s):  
Sensory Processing ◽  
Pyramidal Cell ◽  
Functional Significance ◽  
Functional Role ◽  
Neural Computation ◽  
Inhibitory Interneurons ◽  
Local Circuit ◽  
Processing Function

Inhibitory interneurons are highly diverse, although the functional significance of their diversity is not yet well understood. This presents a barrier to understanding neural computation at the local circuit level. This review focuses on a recent study by Murayama et al. who used a novel in vivo technique in neocortex to demonstrate a specific sensory processing function of dendritic-targeting Martinotti interneurons. The function of Martinotti cells arises from their interaction with layer 5 pyramidal cell dendrites.

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