scholarly journals Mitogen-activated protein kinase (MAPK) blockade of bovine preimplantation embryogenesis requires inhibition of both p38 and extracellular signal-regulated kinase (ERK) pathways

Reproduction ◽  
2005 ◽  
Vol 130 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Pavneesh Madan ◽  
Michele D Calder ◽  
Andrew J Watson

Blastocyst formation, as a critical period during development, is an effective indicator of embryonic health and reproductive efficiency. Out of a number of mechanisms underlying blastocyst formation, highly conserved mitogen-activated protein kinase (MAPK) signaling has emerged as a major mechanism involved in regulating murine preimplantation embryo development. The objective of our study was to ascertain the role of MAPK signaling in regulating bovine development to the blastocyst stage. Using reverse transcriptase PCR and immunohistochemical staining procedures we have demonstrated that mRNA transcripts and polypeptides encoding p38 MAPK pathway constituents are detectable in preimplantation bovine embryos from the one-cell to the blastocyst stage. Further, the effects on bovine embryo development following inhibition of p38 α/β and extracellular signal-regulated kinase (ERK) signaling by treatment with SB220025 and U0126, respectively, were investigated. Eight-cell bovine embryos (50 per group; three replicates) were placed into treatments consisting of synthetic oviductal fluid (SOF) medium: SOF + SB202474 (inactive analogue), SOF + SB220025, SOF + U0124 (inactive analogue), SOF + U0126, and SOF + SB220025 + U0126. Inhibition of p38 MAPK or ERK signaling individually did not affect development to the blastocyst stage. However, when both pathways were blocked simultaneously there was a significant reduction (P< 0.05) in blastocyst formation, cell number and immunofluorescence of phosphorylated downstream pathway constituents. We have determined that, in variance to what was observed during murine preimplantation development, bovine early embryos progress at normal frequencies to the blastocyst stage in the presence of p38 MAPK inhibitors.

2004 ◽  
Vol 24 (3) ◽  
pp. 1081-1095 ◽  
Author(s):  
Nicole H. Purcell ◽  
Dina Darwis ◽  
Orlando F. Bueno ◽  
Judith M. Müller ◽  
Roland Schüle ◽  
...  

ABSTRACT The mitogen-activated protein kinase (MAPK) signaling pathway regulates diverse biologic functions including cell growth, differentiation, proliferation, and apoptosis. The extracellular signal-regulated kinases (ERKs) constitute one branch of the MAPK pathway that has been implicated in the regulation of cardiac differentiated growth, although the downstream mechanisms whereby ERK signaling affects this process are not well characterized. Here we performed a yeast two-hybrid screen with ERK2 bait and a cardiac cDNA library to identify novel proteins involved in regulating ERK signaling in cardiomyocytes. This screen identified the LIM-only factor FHL2 as an ERK interacting protein in both yeast and mammalian cells. In vivo, FHL2 and ERK2 colocalized in the cytoplasm at the level of the Z-line, and interestingly, FHL2 interacted more efficiently with the activated form of ERK2 than with the dephosphorylated form. ERK2 also interacted with FHL1 and FHL3 but not with the muscle LIM protein. Moreover, at least two LIM domains in FHL2 were required to mediate efficient interaction with ERK2. The interaction between ERK2 and FHL2 did not influence ERK1/2 activation, nor was FHL2 directly phosphorylated by ERK2. However, FHL2 inhibited the ability of activated ERK2 to reside within the nucleus, thus blocking ERK-dependent transcriptional responsiveness of ELK-1, GATA4, and the atrial natriuretic factor promoter. Finally, FHL2 partially antagonized the cardiac hypertrophic response induced by activated MEK-1, GATA4, and phenylephrine agonist stimulation. Collectively, these results suggest that FHL2 serves a repressor function in cardiomyocytes through its ability to inhibit ERK1/2 transcriptional coupling.


Author(s):  
И.А. Щепеткин ◽  
О.П. Буданова ◽  
И.Ю. Малышев ◽  
Д.Н. Аточин

В обзоре представлены современные данные о механизмах инициации, регуляции и выполнении процесса апоптоза нейтрофилов с участием «рецепторов смерти», митохондрий, белков семейства Bcl-2, PI3-K (phosphatidylinositol 3-kinase), протеинкиназных каскадов p38 MAPK (mitogen-activated protein kinase), ERK (extracellular signal regulated kinase) и JNK (c-Jun N-terminal kinase), протеинкиназ А, В и С, сAMP, белков теплового шока, NF-kB (nuclear factor-kB), кальпаинов, каспаз и их ингибиторов, активных форм кислорода и других факторов. Предложена гипотетическая модель вовлечения апоптотических процессов в регуляцию дифференцировки и реактивности нейтрофилов. This review presented recent data on initiation, regulation, and execution of neutrophil apoptosis with participation of «death receptors», mitochondria, Bcl-2 family proteins, PI3-K (phosphatidylinositol 3-kinase), p38 MAPK (mitogen-activated protein kinase), ERK (extracellular signal regulated kinase) and JNK (c-Jun N-terminal kinase) cascades, protein kinases A, B and C, сAMP, heat shock proteins, NF-kB (nuclear factor-kB), calpains, caspases and theirs inhibitors, reactive oxygen species, and other factors. A speculative model of the apoptotic processes involvement in the regulation of neutrophil differentiation and reactivity was proposed.


2021 ◽  
Vol 3 (1) ◽  
pp. 27
Author(s):  
Dewi Irawati Soeria Santoso ◽  
Imelda Rosalyn Sianipar ◽  
Neng Tine Kartinah

In recent years, the prevalence of obesity continues to increase, leading to a public health problem. Therefore, the obesity problem needs serious attention and treatment approaches. Exercise is one of the treatment approach to combat obesity because exercise plays a role in beiging/browning process. Beiging is a differentiation process from white adipocyte to beige adipocyte, which has similar characteristics to brown adipocyte and is marked with an increase of UCP-1 expression. Irisin plays a role in increasing UCP-1 expression by activating p38 mitogen-activated protein kinase (MAPK) and extracellular-signal regulated kinase (ERK) signaling. Muscle contraction during exercise can activate PGC-1α, which leads to the synthesis of irisin. Exercise may increase irisin levels in skeletal muscle and consequently, play as a mediator of beiging process in adipose tissue.


2006 ◽  
Vol 26 (6) ◽  
pp. 2408-2418 ◽  
Author(s):  
Matthew Brook ◽  
Carmen R. Tchen ◽  
Tomas Santalucia ◽  
Joanne McIlrath ◽  
J. Simon C. Arthur ◽  
...  

ABSTRACT The p38 mitogen-activated protein kinase (MAPK) signaling pathway, acting through the downstream kinase MK2, regulates the stability of many proinflammatory mRNAs that contain adenosine/uridine-rich elements (AREs). It is thought to do this by modulating the expression or activity of ARE-binding proteins that regulate mRNA turnover. MK2 phosphorylates the ARE-binding and mRNA-destabilizing protein tristetraprolin (TTP) at serines 52 and 178. Here we show that the p38 MAPK pathway regulates the subcellular localization and stability of TTP protein. A p38 MAPK inhibitor causes rapid dephosphorylation of TTP, relocalization from the cytoplasm to the nucleus, and degradation by the 20S/26S proteasome. Hence, continuous activity of the p38 MAPK pathway is required to maintain the phosphorylation status, cytoplasmic localization, and stability of TTP protein. The regulation of both subcellular localization and protein stability is dependent on MK2 and on the integrity of serines 52 and 178. Furthermore, the extracellular signal-regulated kinase (ERK) pathway synergizes with the p38 MAPK pathway to regulate both stability and localization of TTP. This effect is independent of kinases that are known to be synergistically activated by ERK and p38 MAPK. We present a model for the actions of TTP and the p38 MAPK pathway during distinct phases of the inflammatory response.


2006 ◽  
Vol 17 (2) ◽  
pp. 645-657 ◽  
Author(s):  
Sarah E. Robertson ◽  
Subba Rao Gangi Setty ◽  
Anand Sitaram ◽  
Michael S. Marks ◽  
Robert E. Lewis ◽  
...  

Extracellular signal-regulated kinase (Erk) is widely recognized for its central role in cell proliferation and motility. Although previous work has shown that Erk is localized at endosomal compartments, no role for Erk in regulating endosomal trafficking has been demonstrated. Here, we report that Erk signaling regulates trafficking through the clathrin-independent, ADP-ribosylation factor 6 (Arf6) GTPase-regulated endosomal pathway. Inactivation of Erk induced by a variety of methods leads to a dramatic expansion of the Arf6 endosomal recycling compartment, and intracellular accumulation of cargo, such as class I major histocompatibility complex, within the expanded endosome. Treatment of cells with the mitogen-activated protein kinase kinase (MEK) inhibitor U0126 reduces surface expression of MHCI without affecting its rate of endocytosis, suggesting that inactivation of Erk perturbs recycling. Furthermore, under conditions where Erk activity is inhibited, a large cohort of Erk, MEK, and the Erk scaffold kinase suppressor of Ras 1 accumulates at the Arf6 recycling compartment. The requirement for Erk was highly specific for this endocytic pathway, because its inhibition had no effect on trafficking of cargo of the classical clathrin-dependent pathway. These studies reveal a previously unappreciated link of Erk signaling to organelle dynamics and endosomal trafficking.


2021 ◽  
Vol 14 ◽  
Author(s):  
Shuji Wakatsuki ◽  
Toshiyuki Araki

Small non-coding vault RNAs (vtRNAs) have been described as a component of the vault complex, a hollow-and-barrel-shaped ribonucleoprotein complex found in most eukaryotes. It has been suggested that the function of vtRNAs might not be limited to simply maintaining the structure of the vault complex. Despite the increasing research on vtRNAs, little is known about their physiological functions. Recently, we have shown that murine vtRNA (mvtRNA) up-regulates synaptogenesis by activating the mitogen activated protein kinase (MAPK) signaling pathway. mvtRNA binds to and activates mitogen activated protein kinase 1 (MEK1), and thereby enhances MEK1-mediated extracellular signal-regulated kinase activation. Here, we introduce the regulatory mechanism of MAPK signaling in synaptogenesis by vtRNAs and discuss the possibility as a novel molecular basis for synapse formation.


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