scholarly journals Selective expression of the scaffold protein JSAP1 in spermatogonia and spermatocytes

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Munkhuu Bayarsaikhan ◽  
Akiko Shiratsuchi ◽  
Davaakhuu Gantulga ◽  
Yoshinobu Nakanishi ◽  
Katsuji Yoshioka

Scaffold proteins of mitogen-activated protein kinase (MAPK) intracellular signal transduction pathways mediate the efficient and specific activation of the relevant MAPK signaling modules. Previously, our group and others have identified c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3) as a scaffold protein for JNK MAPK pathways. Although JSAP1 is expressed in the testis in adults, its expression during development has not been investigated. In addition, it is unknown which types of cells in the testis express the scaffold protein. Here, we examined the expression of JSAP1 in the testis of mice aged 14 days, 20 days, 6 weeks, and 12 weeks by immunohistochemistry and Western blotting. The specificity of the anti-JSAP1 antibody was evaluated from its reactivity to exogenously expressed JSAP1 and a structurally related protein, and by antigen-absorption experiments. The immunohistochemical analyses with the specific antibody showed that the JSAP1 protein was selectively expressed in the spermatogonia and spermatocytes, but not in other cell types, including spermatids and somatic cells, during development. However, not all spermatogonia and spermatocytes were immunopositive either, especially in the 12-week-old mouse testis. Furthermore, we found by Western blotting that the expression levels of JSAP1 protein vary during development; there is high expression until 6 weeks after birth, which approximately corresponds to the end of the first wave of spermatogenesis. Collectively, these results suggest that JSAP1 function may be important in spermatogenic cells during early postnatal development.

2001 ◽  
Vol 152 (4) ◽  
pp. 765-776 ◽  
Author(s):  
Winfried Wunderlich ◽  
Irene Fialka ◽  
David Teis ◽  
Arno Alpi ◽  
Andrea Pfeifer ◽  
...  

We have identified a novel, highly conserved protein of 14 kD copurifying with late endosomes/lysosomes on density gradients. The protein, now termed p14, is peripherally associated with the cytoplasmic face of late endosomes/lysosomes in a variety of different cell types. In a two-hybrid screen with p14 as a bait, we identified the mitogen-activated protein kinase (MAPK) scaffolding protein MAPK/extracellular signal–regulated kinase (ERK) kinase (MEK) partner 1 (MP1) as an interacting protein. We confirmed the specificity of this interaction in vitro by glutathione S-transferase pull-down assays and by coimmunoprecipitation, cosedimentation on glycerol gradients, and colocalization. Moreover, expression of a plasma membrane–targeted p14 causes mislocalization of coexpressed MP1. In addition, we could reconstitute protein complexes containing the p14–MP1 complex associated with ERK and MEK in vitro. The interaction between p14 and MP1 suggests a MAPK scaffolding activity localized to the cytoplasmic surface of late endosomes/lysosomes, thereby combining catalytic scaffolding and subcellular compartmentalization as means to modulate MAPK signaling within a cell.


2009 ◽  
Vol 133 (11) ◽  
pp. 1850-1856
Author(s):  
Yongdong Feng ◽  
Jianguo Wen ◽  
Chung-Che(Jeff) Chang

Abstract Context.—p38 mitogen-activated protein kinase (MAPK) signaling has been implicated in responses ranging from apoptosis to cell cycle, induction of expression of cytokine genes, and differentiation. This plethora of activators conveys the complexity of the p38 pathway. This complexity is further complicated by the observation that the downstream effects of p38 MAPK activation may be different depending on types of stimuli, cell types, and various p38 MAPK isoforms involved. Objective.—This review focuses on the recent advancement of the p38 MAPK isoforms as well as the roles of p38 MAPK in hematologic malignancies. Data Sources.—Review of pertinent published literature and work in our laboratory. Conclusions.—In some hematologic malignancies, activation of p38 plays a key role in promoting or inhibiting proliferation and also in increasing resistance to chemotherapeutic agents. The importance of different p38 isoforms in various cellular functions has been acknowledged recently. Further understanding of these isoforms will allow the design of more specific inhibitors to target particular isoforms to maximize the treatment effect and minimize the side effects for treating hematopoietic malignancies.


2021 ◽  
Vol 10 ◽  
Author(s):  
Beili Xu ◽  
Shuyu Li ◽  
Yong Fang ◽  
Yanting Zou ◽  
Dongqiang Song ◽  
...  

ObjectiveTo examine the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) on gastric cancer (GC) progression and prognosis, and to explore the underlying mechanism.MethodsPCSK9 expression levels in human GC tissues were determined by quantitative real-time PCR, western blotting, and immunohistochemical assay. PCSK9 serum levels were detected by enzyme-linked immunosorbent assay. The relationships of PCSK9 and GC progression and survival were analyzed using the Chi-square test, Kaplan-Meier analysis, and Cox proportional hazards model. The effect of PCSK9 on cell invasion, migration, and apoptosis were determined in human GC cell lines and mouse xenograft model separately using PCSK9 knockdown and overexpression strategies. The PCSK9 interacting molecules, screened by co-immunoprecipitation combined with LC-MS/MS, were identified by immunofluorescence localization and western blotting. Additionally, the mitogen-activated protein kinase (MAPK) pathway was assessed by western blotting.ResultsPCSK9 mRNA and protein levels were significantly elevated in GC tissues compared with the paired normal tissues at our medical center (P < 0.001). Notably, the up-regulation of PCSK9 expression in GC tissues was related to tumor progression and poor survival. GC patients had higher serum levels of PCSK9 than the age-matched healthy controls (P < 0.001); PCSK9 promoted invasive and migratory ability and inhibited apoptosis in GC cells with no apparent affection in cell proliferation. The silencing of PCSK9 reversed these effects, suppressing tumor metastasis in vitro and in vivo. Furthermore, PCSK9 maintained these functions through up-regulating heat shock protein 70 (HSP70), ultimately facilitating the mitogen-activated protein kinase (MAPK) pathway.ConclusionCollectively, our data revealed that high PCSK9 expression levels in GC tissue were correlated with GC progression and poor prognosis and that PCSK9 could promote GC metastasis and suppress apoptosis by facilitating MAPK signaling pathway through HSP70 up-regulation. PCSK9 may represent a novel potential therapeutic target in GC.


2019 ◽  
Vol 20 (10) ◽  
pp. 2490 ◽  
Author(s):  
Wen-Chung Huang ◽  
Chun-Hsun Huang ◽  
Sindy Hu ◽  
Hui-Ling Peng ◽  
Shu-Ju Wu

Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.


2021 ◽  
Vol 22 (8) ◽  
pp. 4211
Author(s):  
Yen-Tze Liu ◽  
Hsin-Yu Ho ◽  
Chia-Chieh Lin ◽  
Yi-Ching Chuang ◽  
Yu-Sheng Lo ◽  
...  

Platyphyllenone is a type of diarylheptanoid that exhibits anti-inflammatory and chemoprotective effects. However, its effect on oral cancer remains unclear. In this study, we investigated whether platyphyllenone can promote apoptosis and autophagy in SCC-9 and SCC-47 cells. We found that it dose-dependently promoted the cleavage of PARP; caspase-3, -8, and -9 protein expression; and also led to cell cycle arrest at the G2/M phase. Platyphyllenone up-regulated LC3-II and p62 protein expression in both SCC-9 and SCC-47 cell lines, implying that it can induce autophagy. Furthermore, the results demonstrated that platyphyllenone significantly decreased p-AKT and increased p-JNK1/2 mitogen-activated protein kinase (MAPK) signaling pathway in a dose-dependent manner. The specific inhibitors of p-JNK1/2 also reduced platyphyllenone-induced cleavage of PARP, caspase-3, and caspase -8, LC3-II and p62 protein expression. These findings are the first to demonstrate that platyphyllenone can induce both autophagy and apoptosis in oral cancers, and it is expected to provide a therapeutic option as a chemopreventive agent against oral cancer proliferation.


2018 ◽  
Vol 87 (1) ◽  
Author(s):  
Mingyu Hou ◽  
Wenhui Wang ◽  
Feizi Hu ◽  
Yuanxing Zhang ◽  
Dahai Yang ◽  
...  

ABSTRACT Bacterial phosphothreonine lyases have been identified to be type III secretion system (T3SS) effectors that irreversibly dephosphorylate host mitogen-activated protein kinase (MAPK) signaling to promote infection. However, the effects of phosphothreonine lyase on nuclear factor κB (NF-κB) signaling remain largely unknown. In this study, we detected significant phosphothreonine lyase-dependent p65 degradation during Edwardsiella piscicida infection in macrophages, and this degradative effect was blocked by the protease inhibitor MG132. Further analysis revealed that phosphothreonine lyase promotes the dephosphorylation and ubiquitination of p65 by inhibiting the phosphorylation of mitogen- and stress-activated protein kinase-1 (MSK1) and by inhibiting the phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2), p38α, and c-Jun N-terminal kinase (JNK). Moreover, we revealed that the catalytic active site of phosphothreonine lyase plays a critical role in regulating the MAPK-MSK1-p65 signaling axis. Collectively, the mechanism described here expands our understanding of the pathogenic effector in not only regulating MAPK signaling but also regulating p65. These findings uncover a new mechanism by which pathogenic bacteria overcome host innate immunity to promote pathogenesis.


2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
Author(s):  
Xiaoban Xin ◽  
Lijun Zhou ◽  
Caleb M. Reyes ◽  
Feng Liu ◽  
Lily Q. Dong

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.


2018 ◽  
Vol 86 (4) ◽  
Author(s):  
Bikash Sahay ◽  
Kathleen Bashant ◽  
Nicole L. J. Nelson ◽  
Rebeca L. Patsey ◽  
Shiva Kumar Gadila ◽  
...  

ABSTRACTHost genotype influences the severity of murine Lyme borreliosis, caused by the spirochetal bacteriumBorrelia burgdorferi. C57BL/6 (B6) mice develop mild Lyme arthritis, whereas C3H/HeN (C3H) mice develop severe Lyme arthritis. Differential expression of interleukin 10 (IL-10) has long been associated with mouse strain differences in Lyme pathogenesis; however, the underlying mechanism(s) of this genotype-specific IL-10 regulation remained elusive. Herein we reveal a cAMP-mediated mechanism of IL-10 regulation in B6 macrophages that is substantially diminished in C3H macrophages. Under cAMP and CD14-p38 mitogen-activated protein kinase (MAPK) signaling, B6 macrophages stimulated withB. burgdorferiproduce increased amounts of IL-10 and decreased levels of arthritogenic cytokines, including tumor necrosis factor (TNF). cAMP relaxes chromatin, while p38 increases binding of the transcription factors signal transducer and activator of transcription 3 (STAT3) and specific protein 1 (SP1) to the IL-10 promoter, leading to increased IL-10 production in B6 bone marrow-derived monocytes (BMDMs). Conversely, macrophages derived from arthritis-susceptible C3H mice possess significantly less endogenous cAMP, produce less IL-10, and thus are ill equipped to mitigate the damaging consequences ofB. burgdorferi-induced TNF. Intriguingly, an altered balance between anti-inflammatory and proinflammatory cytokines and CD14-dependent regulatory mechanisms also is operative in primary human peripheral blood-derived monocytes, providing potential insight into the clinical spectrum of human Lyme disease. In line with this notion, we have demonstrated that cAMP-enhancing drugs increase IL-10 production in myeloid cells, thus curtailing inflammation associated with murine Lyme borreliosis. Discovery of novel treatments or repurposing of FDA-approved cAMP-modulating medications may be a promising avenue for treatment of patients with adverse clinical outcomes, including certain post-Lyme complications, in whom dysregulated immune responses may play a role.


2021 ◽  
Vol 13 (3) ◽  
pp. 463-472
Author(s):  
Fengting Yin ◽  
Xiaokun Li ◽  
Weili Zhang

This study aimed to explore the analgesic effect of snake neurotoxin combined with gabapentin (Gab) on neuropathic pain in rats with chronic compression injury (CCI) of the sciatic nerve based on the nanotechnology. Firstly, various solutions were prepared to obtain the inner water phase, the oil phase, the outer water phase, and the dilution phase. Poly(lactic-co-glycolic) Acid (PLGA) and polyethylene glycol-poly(lactic-co-glycolic) acid (PEG-PLGA) were added to the prepared oil phase solution to obtain the PLGA snake neurotoxin nanocapsule and PEG-PLGA snake neurotoxin nanocapsule, respectively. After the nanocapsules were obtained, a rat CCI model was further modelled, and the reactive oxygen species (ROS) content in the rat brain tissue was analyzed and tested by the kit, and the optimal physical conditions for preparing the nanocapsules were tested. In order to test the effect of nanocapsules on the p38 mitogen-activated protein kinase (MAPK) signaling pathway, the rats were divided into Control group, Sham group, CCI group, Gabapentin (Gab) group, and PEG-PLGA snake neurotoxin nanocapsule + Gab group. The rats in different groups were given abdominal injections to compare relevant indicators of signal pathway. In the experiment, neuropathic pain was related to changes in ROS content, and snake neurotoxin nanocapsules could reduce the ROS content; PLGA snake neurotoxin nanocapsules and PEG-PLGA snake neurotoxin nanocapsules had encapsulation efficiencys of 24.7% and 22.8% and drug loading of 3.28% and 3.02%, respectively, and the particle sizes of prepared nanocapsules were 760 nm~1,150 nm. Besides, the phase transition temperature of about 50 °C and the light time of 1 h can accelerate the release of nanocapsules to the greatest extent; and the snake neurotoxin could inhibit the activation of p38 MAPK signaling pathway so as to play the analgesic effects on neuropathic pain.


2019 ◽  
Vol 11 (483) ◽  
pp. eaaq1238 ◽  
Author(s):  
David H. Peng ◽  
Samrat T. Kundu ◽  
Jared J. Fradette ◽  
Lixia Diao ◽  
Pan Tong ◽  
...  

Mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitors have failed to show clinical benefit in Kirsten rat sarcoma (KRAS) mutant lung cancer due to various resistance mechanisms. To identify differential therapeutic sensitivities between epithelial and mesenchymal lung tumors, we performed in vivo small hairpin RNA screens, proteomic profiling, and analysis of patient tumor datasets, which revealed an inverse correlation between mitogen-activated protein kinase (MAPK) signaling dependency and a zinc finger E-box binding homeobox 1 (ZEB1)–regulated epithelial-to-mesenchymal transition. Mechanistic studies determined that MAPK signaling dependency in epithelial lung cancer cells is due to the scaffold protein interleukin-17 receptor D (IL17RD), which is directly repressed by ZEB1. Lung tumors in multiple Kras mutant murine models with increased ZEB1 displayed low IL17RD expression, accompanied by MAPK-independent tumor growth and therapeutic resistance to MEK inhibition. Suppression of ZEB1 function with miR-200 expression or the histone deacetylase inhibitor mocetinostat sensitized resistant cancer cells to MEK inhibition and markedly reduced in vivo tumor growth, showing a promising combinatorial treatment strategy for KRAS mutant cancers. In human lung tumor samples, high ZEB1 and low IL17RD expression correlated with low MAPK signaling, presenting potential markers that predict patient response to MEK inhibitors.


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