Induction of B7-H1 expression by human cytomegalovirus in extravillous cytotrophoblast cells and role of MAPK pathway

Abstract Background Let-7a-5p is demonstrated to be a tumor inhibitor in nasopharyngeal carcinoma. However, the role of let-7a-5p in chronic rhinosinusitis with nasal polyps (CRSwNP) has not been reported. This study is designed to determine the pattern of expression and role of let-7a-5p in CRSwNP. Methods The expression level of let-7a-5p, TNF-α, IL-1β, and IL-6 in CRSwNP tissues and cells were detected by RT-qPCR. Western blot assay was carried out to measure the protein expression of the Ras-MAPK pathway. Dual luciferase reporter assay and RNA pull-down assay were used to explore the relationship between let-7a-5p and IL-6. Results Let-7a-5p was significantly downregulated in CRSwNP tissues and cells. Moreover, the mRNA expression of TNF-α, IL-1β and IL-6 was increased in CRSwNP tissues, while let-7a-5p mimic inhibited the expression of TNF-α, IL-1β and IL-6. Besides that, let-7a-5p was negatively correlated with TNF-α, IL-1β and IL-6 in CRSwNP tissues. In our study, IL-6 was found to be a target gene of let-7a-5p. Additionally, let-7-5p mimic obviously reduced the protein levels of Ras, p-Raf1, p-MEK1 and p-ERK1/2, while IL-6 overexpression destroyed the inhibitory effect of let-7a-5p on the Ras-MAPK pathway in CRSwNP. Conclusion We demonstrated that let-7a-5p/IL-6 interaction regulated the inflammatory response through the Ras-MAPK pathway in CRSwNP.

Download Full-text

Role of Envelope Glycoprotein Complexes in Cell-Associated Spread of Human Cytomegalovirus

Viruses ◽

10.3390/v13040614 ◽

2021 ◽

Vol 13 (4) ◽

pp. 614

Author(s):

Nina Weiler ◽

Caroline Paal ◽

Kerstin Adams ◽

Christopher Calcaterra ◽

Dina Fischer ◽

...

Keyword(s):

Human Cytomegalovirus ◽

Envelope Glycoprotein ◽

Infectious Virus ◽

Viral Envelope ◽

Accessory Proteins ◽

Viral Growth ◽

Cell Association ◽

Quantitative Immunoblotting ◽

Model Virus

The role of viral envelope glycoproteins, particularly the accessory proteins of trimeric and pentameric gH/gL-complexes, in cell-associated spread of human cytomegalovirus (HCMV) is unclear. We aimed to investigate their contribution in the context of HCMV variants that grow in a strictly cell-associated manner. In the genome of Merlin pAL1502, the glycoproteins gB, gH, gL, gM, and gN were deleted by introducing stop codons, and the mutants were analyzed for viral growth. Merlin and recent HCMV isolates were compared by quantitative immunoblotting for expression of accessory proteins of the trimeric and pentameric gH/gL-complexes, gO and pUL128. Isolates were treated with siRNAs against gO and pUL128 and analyzed regarding focal growth and release of infectious virus. All five tested glycoproteins were essential for growth of Merlin pAL1502. Compared with this model virus, higher gO levels were measured in recent isolates of HCMV, and its knockdown decreased viral growth. Knockdown of pUL128 abrogated the strict cell-association and led to release of infectivity, which allowed cell-free transfer to epithelial cells where the virus grew again strictly cell-associated. We conclude that both trimer and pentamer contribute to cell-associated spread of recent clinical HCMV isolates and downregulation of pentamer can release infectious virus into the supernatant.

Download Full-text

Differential role of SIRT1/MAPK pathway during cerebral ischemia in rats and humans

Scientific Reports ◽

10.1038/s41598-021-85577-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sireesh Kumar Teertam ◽

Phanithi Prakash Babu

Keyword(s):

Cerebral Ischemia ◽

Caspase 3 ◽

Mapk Pathway ◽

Protective Role ◽

Akt Signaling ◽

Sirtuin 1 ◽

Neurological Dysfunction ◽

Dependent Manner ◽

Erk Mapk

AbstractCerebral ischemia (CI) is a severe cause of neurological dysfunction and mortality. Sirtuin-1 (Silent information regulator family protein 1, SIRT1), an oxidized nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase, plays an important role in protection against several neurodegenerative disorders. The present study aims to investigate the protective role of SIRT1 after CI in experimental young and aged rats and humans. Also, the study examines the possible regulatory mechanisms of neuronal death in CI settings. Immunoblotting and immunohistochemistry were used to evaluate changes in the expression of SIRT1, JNK/ERK/MAPK/AKT signaling, and pro-apoptotic caspase-3 in experimental rats and CI patients. The study findings demonstrated that, in aged experimental rats, SIRT1 activation positively influenced JNK and ERK phosphorylation and modulated neuronal survival in AKT-dependent manner. Further, the protection conferred by SIRT1 was effectively reversed by JNK inhibition and increased pro-apoptotic caspase-3 expression. In young experimental rats, SIRT1 activation decreased the phosphorylation of stress-induced JNK, ERK, caspase-3, and increased the phosphorylation of AKT after CI. Inhibition of SIRT1 reversed the protective effect of resveratrol. More importantly, in human patients, SIRT1 expression, phosphorylation of JNK/ERK/MAPK/AKT signaling and caspase-3 were up-regulated. In conclusion, SIRT1 could possibly be involved in the modulation of JNK/ERK/MAPK/AKT signaling pathway in experimental rats and humans after CI.

Download Full-text

Potential role of human cytomegalovirus and p53 interaction in coronary restenosis

Science ◽

10.1126/science.8023160 ◽

1994 ◽

Vol 265 (5170) ◽

pp. 391-394 ◽

Cited By ~ 522

Author(s):

E Speir ◽

R Modali ◽

E. Huang ◽

M. Leon ◽

F Shawl ◽

...

Keyword(s):

Human Cytomegalovirus ◽

Potential Role ◽

Coronary Restenosis

Download Full-text

Activating mutations in BRAF disrupt the hypothalamo-pituitary axis leading to hypopituitarism in mice and humans

Nature Communications ◽

10.1038/s41467-021-21712-4 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Angelica Gualtieri ◽

Nikolina Kyprianou ◽

Louise C. Gregory ◽

Maria Lillina Vignola ◽

James G. Nicholson ◽

...

Keyword(s):

Mapk Pathway ◽

Critical Role ◽

Cell Lineage ◽

Activating Mutations ◽

Pathway Activation ◽

Tumour Formation ◽

Conditional Expression ◽

Cell Cycle Inhibitors ◽

Mutation Braf

AbstractGermline mutations in BRAF and other components of the MAPK pathway are associated with the congenital syndromes collectively known as RASopathies. Here, we report the association of Septo-Optic Dysplasia (SOD) including hypopituitarism and Cardio-Facio-Cutaneous (CFC) syndrome in patients harbouring mutations in BRAF. Phosphoproteomic analyses demonstrate that these genetic variants are gain-of-function mutations leading to activation of the MAPK pathway. Activation of the MAPK pathway by conditional expression of the BrafV600E/+ allele, or the knock-in BrafQ241R/+ allele (corresponding to the most frequent human CFC-causing mutation, BRAF p.Q257R), leads to abnormal cell lineage determination and terminal differentiation of hormone-producing cells, causing hypopituitarism. Expression of the BrafV600E/+ allele in embryonic pituitary progenitors leads to an increased expression of cell cycle inhibitors, cell growth arrest and apoptosis, but not tumour formation. Our findings show a critical role of BRAF in hypothalamo-pituitary-axis development both in mouse and human and implicate mutations found in RASopathies as a cause of endocrine deficiencies in humans.

Download Full-text

Central Role of the MAPK Pathway in Ang II–Mediated DNA Synthesis and Migration in Rat Vascular Smooth Muscle Cells

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/01.atv.19.1.73 ◽

1999 ◽

Vol 19 (1) ◽

pp. 73-82 ◽

Cited By ~ 82

Author(s):

Xiao-Ping Xi ◽

Kristof Graf ◽

Stephan Goetze ◽

Eckart Fleck ◽

Willa A. Hsueh ◽

...

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Dna Synthesis ◽

Vascular Smooth Muscle Cells ◽

Mapk Pathway ◽

Muscle Cells ◽

Ang Ii ◽

And Migration

Download Full-text

Stimulation of pro-α1(I) collagen by TGF-β1 in mesangial cells: role of the p38 MAPK pathway

AJP Renal Physiology ◽

10.1152/ajprenal.2001.280.3.f495 ◽

2001 ◽

Vol 280 (3) ◽

pp. F495-F504 ◽

Cited By ~ 92

Author(s):

Beek Yoke Chin ◽

Amir Mohsenin ◽

Su Xia Li ◽

Augustine M. K. Choi ◽

Mary E. Choi

Keyword(s):

P38 Mapk ◽

Intracellular Signaling ◽

Mesangial Cells ◽

Mapk Pathway ◽

Dominant Negative ◽

Glomerular Mesangial Cells ◽

Mapk Activation ◽

Mapk Phosphorylation ◽

Collagen Mrna

Transforming growth factor-β1(TGF-β1) is a potent inducer of extracellular matrix protein synthesis and a key mediator of renal fibrosis. However, the intracellular signaling mechanisms by which TGF-β1stimulates this process remain incompletely understood. In this report, we examined the role of a major stress-activated intracellular signaling cascade, belonging to the mitogen-activated protein kinase (MAPK) superfamily, in mediating TGF-β1 responses in rat glomerular mesangial cells, using dominant-negative inhibition of TGF-β1 signaling receptors. We first stably transfected rat glomerular mesangial cells with a kinase-deleted mutant TGF-β type II receptor (TβR-IIM) designed to inhibit TGF-β1 signaling in a dominant-negative fashion. Next, expression of TβR-IIM mRNA was confirmed by Northern analysis. Cell surface expression and ligand binding of TβR-IIM protein were demonstrated by affinity cross-linking with 125I-labeled-TGF-β1. TGF-β1 rapidly induced p38 MAPK phosphorylation in wild-type and empty vector (pcDNA3)-transfected control mesangial cells. Interestingly, transfection with dominant-negative TβR-IIM failed to block TGF-β1-induced p38 MAPK phosphorylation. Moreover, dominant-negative TβR-IIMfailed to block TGF-β1-stimulated pro-α1(I) collagen mRNA expression and cellular protein synthesis, whereas TGF-β1-induced extracellular signal-regulated kinase (ERK) 1/ERK2 activation and antiproliferative responses were blocked by TβR-IIM. In the presence of a specific inhibitor of p38 MAPK, SB-203580, TGF-β1 was unable to stimulate pro-α1(I) collagen mRNA expression in the control and TβR-IIM-transfected mesangial cells. Finally, we confirmed that both p38 MAPK activation and pro-α1(I) collagen stimulation were TGF-β1 effects that were abrogated by dominant-negative inhibition of TGF-β type I receptor. Thus we show first demonstration of p38 MAPK activation by TGF-β1 in mesangial cells, and, given the rapid kinetics, this TGF-β1 effect is likely a direct one. Furthermore, our findings suggest that the p38 MAPK pathway functions as a component in the signaling of pro-α1(I) collagen induction by TGF-β1 in mesangial cells.

Download Full-text