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1.
Virus Res ; 345: 199379, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38643859

ABSTRACT

Although all herpesviruses utilize a highly conserved replication machinery to amplify their viral genomes, different members may have unique strategies to modulate the assembly of their replication components. Herein, we characterize the subcellular localization of seven essential replication proteins of varicella-zoster virus (VZV) and show that several viral replication enzymes such as the DNA polymerase subunit ORF28, when expressed alone, are localized in the cytoplasm. The nuclear import of ORF28 can be mediated by the viral DNA polymerase processivity factor ORF16. Besides, ORF16 could markedly enhance the protein abundance of ORF28. Noteworthily, an ORF16 mutant that is defective in nuclear transport still retained the ability to enhance ORF28 abundance. The low abundance of ORF28 in transfected cells was due to its rapid degradation mediated by the ubiquitin-proteasome system. We additionally reveal that radicicol, an inhibitor of the chaperone Hsp90, could disrupt the interaction between ORF16 and ORF28, thereby affecting the nuclear entry and protein abundance of ORF28. Collectively, our findings imply that the cytoplasmic retention and rapid degradation of ORF28 may be a key regulatory mechanism for VZV to prevent untimely viral DNA replication, and suggest that Hsp90 is required for the interaction between ORF16 and ORF28.


Subject(s)
Active Transport, Cell Nucleus , DNA-Directed DNA Polymerase , Herpesvirus 3, Human , Viral Proteins , Virus Replication , Herpesvirus 3, Human/genetics , Herpesvirus 3, Human/metabolism , Humans , Viral Proteins/metabolism , Viral Proteins/genetics , DNA-Directed DNA Polymerase/metabolism , DNA-Directed DNA Polymerase/genetics , Cell Nucleus/metabolism , Cell Nucleus/virology , Cytoplasm/metabolism , Cytoplasm/virology , Cell Line , DNA Replication
2.
Int J Cancer ; 154(9): 1639-1651, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38212905

ABSTRACT

TRPS1 is aberrantly expressed in a variety of tumors, including breast, prostate, and gastric cancers, and is strongly associated with tumorigenesis or prognosis. However, the role of TRPS1 in high grade serous ovarian carcinoma (HGSC) is unknown. We investigated the relationship between TRPS1 expression and clinicopathology in HGSC patients. The tumor-related regulatory mechanisms of TRPS1 was explored through in vivo and vitro experiments. The results showed that TRPS1 was highly expressed in HGSC compared to normal tissues. It was also linked to the cell proliferation index Ki67 and poor prognosis. In vivo experiments showed that knockdown of TRPS1 could inhibit tumor growth. In vitro experiments, knockdown of TRPS1 inhibited the proliferation of ovarian cancer cells. TRPS1 exerted its regulatory role as a transcription factor, binding to the PSAT1 promoter and promoting the expression of PSAT1 gene. Meanwhile, PSAT1 was positively correlated with CCND1 expression. These results suggest that TRPS1 affects HGSC proliferation and cell cycle by regulating PSAT1 and thus CCND1 expression.


Subject(s)
Cystadenocarcinoma, Serous , Ovarian Neoplasms , Male , Female , Humans , Cystadenocarcinoma, Serous/pathology , Ovarian Neoplasms/pathology , Transcription Factors/genetics , Prognosis , Cell Proliferation , Repressor Proteins/genetics
3.
Microbiol Spectr ; 11(6): e0225423, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-37874136

ABSTRACT

IMPORTANCE: Eukaryotic DNA replication is a highly regulated process that requires multiple replication enzymes assembled onto DNA replication origins. Due to the complexity of the cell's DNA replication machinery, most of what we know about cellular DNA replication has come from the study of viral systems. Herein, we focus our study on the assembly of the Kaposi's sarcoma-associated herpesvirus core replication complex and propose a pairwise protein-protein interaction network of six highly conserved viral core replication proteins. A detailed understanding of the interaction and assembly of the viral core replication proteins may provide opportunities to develop new strategies against viral propagation.


Subject(s)
Herpesvirus 8, Human , Herpesvirus 8, Human/genetics , Herpesvirus 8, Human/metabolism , Viral Proteins/genetics , DNA Replication
4.
Cell Biol Toxicol ; 39(6): 3141-3157, 2023 12.
Article in English | MEDLINE | ID: mdl-37531013

ABSTRACT

Infertility has attracted global concern, and disruption of testosterone is a common cause of male infertility. Exploring the critical factors in testosterone biosynthesis may provide new insights for disease research and clinical therapy. Research on trichorhinophalangeal syndrome-1 (Trps1) gene has recently been focus on cancers; it is yet unknown whether Trps1 produces a marked effect in the male reproductive system. In the current study, single-cell RNA sequencing analysis of trichorhinophalangeal syndrome-1 gene (Trps1) expression in mouse testes and cleavage under targets and tagmentation and RNA sequencing were utilized to investigate the functionality of Trps1 in mouse Leydig cells. Knockdown of Trps1 increased testosterone synthesis in vitro and vivo using adeno-associated viral delivery and conditional knockout models. The results showed that Trps1 was abundantly expressed in Leydig cells. The expression levels of both steroidogenic factor-1 (Sf-1) and steroidogenic enzymes (Cyp11a1, Hsd3b, Cyp17a1, and Hsd17b3) as well as testosterone secretion were increased after Trps1 deficiency in vivo and vitro. Furthermore, disruption of Trps1 reduced histone deacetylase 1/2 activity and increased histone H3 acetylation in the Sf-1 promoter, thereby promoting testosterone secretion. Interestingly, Sf-1 also regulated the transcription of Trps1 through activating transcription factor 2. These results indicate that Trps1 targets Sf-1 to affect steroidogenesis through histone acetylation and shed light on the critical role of Trps1 functioning in the mouse Leydig cells.


Subject(s)
Leydig Cells , Testosterone , Mice , Animals , Male , Leydig Cells/metabolism , Base Sequence , Promoter Regions, Genetic , Repressor Proteins/genetics
5.
Int J Mol Sci ; 23(15)2022 Aug 04.
Article in English | MEDLINE | ID: mdl-35955808

ABSTRACT

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded ORF50 protein is a potent transcriptional activator essential for triggering KSHV lytic reactivation. Despite extensive studies, little is known about whether ORF50 possesses the ability to repress gene expression or has an antagonistic action to cellular transcription factors. Previously, we demonstrated that human oncoprotein MDM2 can promote the degradation of ORF50 protein. Herein, we show that abundant ORF50 expression in cells can conversely downregulate MDM2 expression via repressing both the upstream (P1) and internal (P2) promoters of the MDM2 gene. Deletion analysis of the MDM2 P1 promoter revealed that there were two ORF50-dependent negative response elements located from -102 to -63 and from -39 to +1, which contain Sp1-binding sites. For the MDM2 P2 promoter, the ORF50-dependent negative response element was identified in the region from -110 to -25, which is coincident with the location of two known p53-binding sites. Importantly, we further demonstrated that overexpression of Sp1 or p53 in cells indeed upregulated MDM2 expression; however, coexpression with ORF50 protein remarkably reduced the Sp1- or p53-mediated MDM2 upregulation. Collectively, our findings propose a reciprocal negative regulation between ORF50 and MDM2 and uncover that ORF50 decreases MDM2 expression through repressing Sp1- and p53-mediated transactivation.


Subject(s)
Herpesvirus 8, Human , Gene Expression Regulation, Viral , Herpesvirus 8, Human/genetics , Humans , Promoter Regions, Genetic , Proto-Oncogene Proteins c-mdm2/genetics , Proto-Oncogene Proteins c-mdm2/metabolism , Response Elements , Sp1 Transcription Factor/genetics , Sp1 Transcription Factor/metabolism , Transcription Factors/metabolism , Transcriptional Activation , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Viral Proteins
6.
Toxicol Appl Pharmacol ; 441: 115969, 2022 04 15.
Article in English | MEDLINE | ID: mdl-35259346

ABSTRACT

Icariin (ICA), extracted from Epimedium, is a flavonoid used in traditional Chinese medicine. Di(2-ethylhexyl) phthalate (DEHP) is a phthalate used in commercial products as a plasticizer that can influence the human endocrine and reproduction system. We previously found that ICA reversed DEHP-induced damage through the prevention of reactive oxygen species accumulation and promotion of testosterone secretion. Here we investigated the mechanisms of ICA in promoting testosterone secretion from murine Leydig cells. We used ICA, DEHP, the Akt agonist SC-79, the Akt inhibitor MK2206, and the Creb inhibitor KG501 to determine the effect of these treatments on the expression levels of the steroidogenic enzymes, Cyp11a1 and Hsd3b, which play critical roles in androgen production, in Leydig cells. Bioinformatic analysis was used to search for ICA-targeted proteins and their associated pathways. We found that icariin interacted with estrogen receptor on the cell membrane, leading to increased phosphorylation levels of Akt and Creb proteins and enhanced transcription of genes encoding steroidogenic enzymes and testosterone synthesis. We further investigated ICA activity in vivo using male mice pretreated with 100 mg/kg ICA and then treated with 750 mg/kg DEHP. ICA pretreatment reversed the reduced protein expression levels of Cyp11a1 and Hsd3b induced by DEHP in Leydig cells in vivo. Furthermore, while the phosphorylation levels of Akt and Creb were decreased in testes of mice exposed to DEHP alone, these effects were reversed by ICA pretreatment. These findings indicate that ICA promotes testosterone synthesis via the Esr1/Src/Akt/Creb/Sf-1 signaling pathway.


Subject(s)
Diethylhexyl Phthalate , Leydig Cells , Animals , Cholesterol Side-Chain Cleavage Enzyme , Diethylhexyl Phthalate/pharmacology , Flavonoids , Male , Mice , Proto-Oncogene Proteins c-akt/metabolism , Testis , Testosterone/metabolism
7.
Microbiol Spectr ; 10(1): e0146421, 2022 02 23.
Article in English | MEDLINE | ID: mdl-35019687

ABSTRACT

The open reading frame 50 (ORF50) protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is the master regulator essential for initiating the viral lytic cycle. Previously, we have demonstrated that the ORF50 protein can cooperate with Sp3 to synergistically activate a set of viral and cellular gene promoters through highly conserved ORF50-responsive elements that harbor a Sp3-binding motif. Herein, we show that Sp3 undergoes proteolytic cleavage during the viral lytic cycle, and the cleavage of Sp3 is dependent on caspase activation. Since similar cleavage patterns of Sp3 could be detected in both KSHV-positive and KSHV-negative lymphoma cells undergoing apoptosis, the proteolytic cleavage of Sp3 could be a common event during apoptosis. Mutational analysis identifies 12 caspase cleavage sites in Sp3, which are situated at the aspartate (D) positions D17, D19, D180, D273, D275, D293, D304 (or D307), D326, D344, D530, D543, and D565. Importantly, we noticed that three stable Sp3 C-terminal fragments generated through cleavage at D530, D543, or D565 encompass an intact DNA-binding domain. Like the full-length Sp3, the C-terminal fragments of Sp3 could still retain the ability to cooperate with ORF50 protein to activate specific viral and cellular gene promoters synergistically. Collectively, our findings suggest that despite the proteolytic cleavage of Sp3 under apoptotic conditions, the resultant Sp3 fragments may retain biological activities important for the viral lytic cycle or for cellular apoptosis. IMPORTANCE The ORF50 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is the key viral protein that controls the switch from latency to lytic reactivation. It is a potent transactivator that can activate target gene promoters via interacting with other cellular DNA-binding transcription factors, such as Sp3. In this report, we show that Sp3 is proteolytically cleaved during the viral lytic cycle, and up to 12 caspase cleavage sites are identified in Sp3. Despite the proteolytic cleavage of Sp3, several resulting C-terminal fragments that have intact zinc-finger DNA-binding domains still retain substantial influence in the synergy with ORF50 to activate specific gene promoters. Overall, our studies elucidate the caspase-mediated cleavage of Sp3 and uncover how ORF50 utilizes the cleavage fragments of Sp3 to transactivate specific viral and cellular gene promoters.


Subject(s)
Caspases/metabolism , Herpesviridae Infections/metabolism , Herpesvirus 8, Human/physiology , Sp3 Transcription Factor/metabolism , Amino Acid Motifs , Amino Acid Sequence , Apoptosis , Caspases/genetics , Gene Expression Regulation, Viral , Herpesviridae Infections/genetics , Herpesviridae Infections/physiopathology , Herpesviridae Infections/virology , Herpesvirus 8, Human/genetics , Host-Pathogen Interactions , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Lymphoma/genetics , Lymphoma/metabolism , Lymphoma/physiopathology , Lymphoma/virology , Sequence Alignment , Sp3 Transcription Factor/chemistry , Sp3 Transcription Factor/genetics , Trans-Activators/genetics , Trans-Activators/metabolism , Virus Latency
8.
Cancer Sci ; 113(4): 1277-1291, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35080085

ABSTRACT

Long noncoding RNAs (lncRNAs) have been found to play an important role in the occurrence and development of endometrial carcinoma (EC). Here, using RNA sequencing analysis, we systemically screened and identified the lncRNA eukaryotic translation initiation factor 1A, X-linked (EIF1AX)-AS1, which is aberrantly downregulated in clinical EC tissues and closely correlated with tumor type. EIF1AX-AS1 markedly inhibited EC cell proliferation and promoted apoptosis in vitro and in vivo. Mechanistically, EIF1AX-AS1 interacts with EIF1AX mRNA and poly C binding protein 1 (PCBP1), which promote EIF1AX mRNA degradation. Intriguingly, by interacting with internal ribosome entry site-related protein Y-box binding protein 1 (YBX-1), EIF1AX promotes c-Myc translation through the internal ribosome entry site pathway. c-Myc promotes EIF1AX transcription and thus forms a feed-forward loop to regulate EC cell proliferation. Taken together, these data reveal new insights into the biology driving EC proliferation and highlights the potential of lncRNAs as biomarkers for prognosis and future therapeutic targets for cancer.


Subject(s)
Endometrial Neoplasms , RNA, Long Noncoding , Apoptosis/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Endometrial Neoplasms/metabolism , Female , Gene Expression Regulation, Neoplastic , Humans , Internal Ribosome Entry Sites , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , RNA, Messenger/genetics , Xenograft Model Antitumor Assays
9.
Oxid Med Cell Longev ; 2022: 1361135, 2022.
Article in English | MEDLINE | ID: mdl-36589683

ABSTRACT

Dysregulation of eukaryotic translation initiation factor 1A, X-linked (EIF1AX), has been implicated in the pathogenesis of some cancers. However, the role of EIF1AX in endometrial carcinoma (EC) remains unknown. We investigated the EIF1AX expression in EC patients and assessed its tumorigenesis-associated function and nucleocytoplasmic transport mechanism in vitro and in vivo. The results indicated that the cytoplasmic EIF1AX expression showed a gradual increase when going from endometrium normal tissue, simple endometrial hyperplasia, complex endometrial hyperplasia, and endometrial atypical hyperplasia to EC, while vice versa for the nuclear EIF1AX expression. In addition, the cytoplasmic EIF1AX expression was positively correlated with histologic type, high International Federation of Gynecology and Obstetrics (FIGO) grade, advanced FIGO stage, deeper infiltration, high Ki67 index, and shorter recurrence-free survival in EC patients. In vitro, short hairpin RNA-mediated EIF1AX depletion or SV40NLS-mediated EIF1AX import into the nucleus in multiple human EC cells potently suppressed cell migration and invasion, epithelial-mesenchymal transition, and lung metastasis. Moreover, exportin 1 induced the transport of EIF1AX from the nucleus to the cytoplasm that could be inhibited by leptomycin B treatment or the mutation in the EIF1AX location sequence. These results demonstrate that cytoplasmic EIF1AX may play a key role in the incidence and promotion of EC, and thus, targeting EIF1AX or its nucleocytoplasmic transport process may offer an effective new therapeutic approach to EC.


Subject(s)
Endometrial Hyperplasia , Endometrial Neoplasms , Eukaryotic Initiation Factor-1 , Receptors, Cytoplasmic and Nuclear , Female , Humans , Cell Line, Tumor , Cell Proliferation , Cytoplasm/metabolism , Endometrial Hyperplasia/metabolism , Endometrial Hyperplasia/pathology , Endometrial Neoplasms/genetics , Endometrium/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Eukaryotic Initiation Factor-1/metabolism , Exportin 1 Protein
10.
J Mol Histol ; 52(5): 965-973, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34405343

ABSTRACT

Preimplantation embryo development is characterized by drastic nuclear reprogramming and dynamic stage-specific gene expression. Key regulators of this earliest developmental stage have not been revealed. In the present study, a "non-classical" nuclear-localization pattern of eIF1A was observed during early developmental stages of mouse preimplantation embryo before late-morula. In particular, eIF1A is most highly expressed in the nuclear of 2-cell embryo. Knockdown eIF1A by siRNA microinjection affected the development of mouse preimplantation embryo, resulted in decreased blastocyst formation rate. CDX2 protein expression level significantly down-regulated after eIF1A knockdown in morula stage. In addition, the mRNA expression level of Hsp70.1 was also decreased in 2-cell embryo. The results indicate an indispensable role of eIF1A in mouse preimplantation embryos.


Subject(s)
Cell Nucleus/metabolism , Embryonic Development , Eukaryotic Initiation Factor-1/metabolism , Animals , Biomarkers/metabolism , Eukaryotic Initiation Factor-1/genetics , Female , Gene Expression Regulation, Developmental , Gene Knockdown Techniques , Genome , Male , Mice , Transcription Factors/metabolism , Zygote/metabolism
11.
Microbiol Spectr ; 9(1): e0042221, 2021 09 03.
Article in English | MEDLINE | ID: mdl-34431704

ABSTRACT

The human norovirus (HuNV)-encoded nucleoside-triphosphatase (NTPase) is a multifunctional protein critically involved in viral replication and pathogenesis. Previously, we have shown that the viral NTPase is capable of forming vesicle clusters in cells, interacting with other viral proteins such as P22, and promoting cellular apoptosis. Herein, we demonstrate that NTPase-associated vesicle clusters correspond to lipid droplets (LDs) wrapped by the viral protein and show that NTPase-induced apoptosis is mediated through both caspase-8- and caspase-9-dependent pathways. Deletion analysis revealed that the N-terminal 179-amino-acid (aa) region of NTPase encompasses two LD-targeting motifs (designated LTM-1 and LTM-2), two apoptosis-inducing motifs, and multiple regulatory regions. Interestingly, the identified LTM-1 and LTM-2, which are located from aa 1 to 50 and from aa 51 to 90, respectively, overlap with the two apoptosis-inducing motifs. Although there was no positive correlation between the extent of LD localization and the degree of cellular apoptosis for NTPase mutants, we noticed that mutant proteins defective in LD-targeting ability could not induce cellular apoptosis. In addition to LD targeting, the amphipathic LTM-1 and LTM-2 motifs could have the potential to direct fusion proteins to the endoplasmic reticulum (ER). Furthermore, we found that the LTM-1 motif is a P22-interacting motif. However, P22 functionally augmented the proapoptotic activity of the LTM-2 fusion protein but not the LTM-1 fusion protein. Overall, our findings propose that NTPase may participate in multiple cellular processes through binding to LDs or to the ER via its N-terminal amphipathic helix motifs. IMPORTANCE Human noroviruses (HuNVs) are the major agent of global gastroenteritis outbreaks. However, due to the lack of an efficient cell culture system for HuNV propagation, functions of the viral-encoded proteins in host cells are still poorly understood. In the current study, we present that the viral NTPase is a lipid droplet (LD)-associated protein, and we identify two LD-targeting motifs, LTM-1 and LTM-2, in its N-terminal domain. In particular, the identified LTM-1 and LTM-2 motifs, which contain a hydrophobic region and an amphipathic helix, are also capable of delivering the fusion protein to the endoplasmic reticulum (ER), promoting cellular apoptosis, and physically or functionally associating with another viral protein P22. Since LDs and the ER have been linked to several biological functions in cells, our study therefore proposes that the norovirus NTPase may utilize LDs or the ER as replication platforms to benefit viral replication and pathogenesis.


Subject(s)
Lipid Droplets/metabolism , Norovirus/enzymology , Nucleoside-Triphosphatase/isolation & purification , Viral Proteins/metabolism , Apoptosis , Endoplasmic Reticulum/metabolism , Gastroenteritis , Humans , Norovirus/genetics , Nucleoside-Triphosphatase/genetics , Virus Replication
12.
Andrology ; 9(6): 1923-1933, 2021 11.
Article in English | MEDLINE | ID: mdl-34185441

ABSTRACT

BACKGROUND: The tricho-rhino-phalangeal syndrome-1 gene (Trps1) is an atypical GATA family member. Although current studies of Trps1 mainly focus on tumors, whether Trps1 plays a role in the male reproductive system remains unknown. OBJECTIVES: The purpose of this study was to elucidate the function of Trps1 in Leydig cells, indicating its regulatory mechanism on the cell cycle. METHODS: Gene-silencing technology, RNA-seq, RT-qPCR, and western blotting were used to evaluate the function of Trps1 in mouse primary Leydig cells and MLTC-1 cells. In addition, ChIP-base sets and ChIP-qPCR were employed to further assess the regulatory mechanism of Trps1 in MLTC-1 cells. RESULTS: Knockdown of Trps1 in Leydig cells significantly suppressed phosphorylation of Src and Akt and expression of Ccnd1, which was accompanied by impairment of cell proliferative ability. Trps1 may affect the cell cycle through the Src/Akt/Ccnd1 signaling pathway. In addition, Trps1 may bind to the promoter of Srcin1 to regulate its transcription, thus influencing Src phosphorylation levels and the proliferation of Leydig cells. DISCUSSION AND CONCLUSION: Src increases in Leydig cells during pubertal development, suggesting its functional involvement in differentiated adult Leydig cells. Inhibition of the Src/Akt pathway would reduce Ccnd1 expression. In the present study, we found that Trps1 may regulate the phosphorylation level of Src and Akt through Srcin1, targeting Ccnd1 to influence mouse Leydig cell proliferation. These findings shed light on the regulation of Trps1 on cell proliferation and differentiation of mouse Leydig cells.


Subject(s)
Cell Proliferation/genetics , Cyclin D1/physiology , Leydig Cells/metabolism , Repressor Proteins/physiology , Animals , Cell Cycle/genetics , Cell Differentiation/genetics , Male , Mice , Signal Transduction/genetics
13.
Int J Mol Sci ; 22(8)2021 Apr 14.
Article in English | MEDLINE | ID: mdl-33919712

ABSTRACT

The unfolded protein response (UPR) is an intracellular signaling pathway essential for alleviating the endoplasmic reticulum (ER) stress. To support the productive infection, many viruses are known to use different strategies to manipulate the UPR signaling network. However, it remains largely unclear whether the UPR signaling pathways are modulated in the lytic cycle of Epstein-Barr virus (EBV), a widely distributed human pathogen. Herein, we show that the expression of GRP78, a central UPR regulator, is up-regulated during the EBV lytic cycle. Our data further revealed that knockdown of GRP78 in EBV-infected cell lines did not substantially affect lytic gene expression; however, GRP78 knockdown in these cells markedly reduced the production of virus particles. Importantly, we identified that the early lytic protein BMLF1 is the key regulator critically contributing to the activation of the grp78 gene promoter. Mechanistically, we found that BMLF1 can trigger the proteolytic cleavage and activation of the UPR senor ATF6, which then transcriptionally activates the grp78 promoter through the ER stress response elements. Our findings therefore provide evidence for the connection between the EBV lytic cycle and the UPR, and implicate that the BMLF1-mediated ATF6 activation may play critical roles in EBV lytic replication.


Subject(s)
Activating Transcription Factor 6/metabolism , Heat-Shock Proteins/genetics , Phosphoproteins/metabolism , Trans-Activators/metabolism , Up-Regulation , Base Sequence , Cell Line, Tumor , Cell Nucleus/metabolism , DNA, Viral/biosynthesis , Endoplasmic Reticulum Chaperone BiP , Endoplasmic Reticulum Stress , Endoribonucleases/metabolism , Gene Expression Regulation, Viral , HEK293 Cells , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/physiology , Humans , Models, Biological , Promoter Regions, Genetic , Protein Serine-Threonine Kinases/metabolism , Protein Transport , Signal Transduction , Transcriptional Activation/genetics , Unfolded Protein Response , Up-Regulation/genetics , eIF-2 Kinase/metabolism
14.
J Virol ; 94(18)2020 08 31.
Article in English | MEDLINE | ID: mdl-32641483

ABSTRACT

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded open reading frame 50 (ORF50) protein is the key transactivator responsible for the latent-to-lytic switch. Here, we investigated the transcriptional activation of the ORF56 gene (encoding a primase protein) by ORF50 and successfully identified an ORF50-responsive element located in the promoter region between positions -97 and -44 (designated 56p-RE). This 56p-RE element contains a noncanonical RBP-Jκ-binding sequence and a nonconsensus Sp1/Sp3-binding sequence. Electrophoretic mobility shift assays revealed that RBP-Jκ, Sp3, and ORF50 could form stable complexes on the 56p-RE element. Importantly, transient-reporter analysis showed that Sp3, but not RBP-Jκ or Sp1, acts in synergy with ORF50 to activate the 56p-RE-containing reporter construct, and the synergy mainly depends on the Sp1/Sp3-binding region of the 56p-RE element. Sequence similarity searches revealed that the promoters for ORF21 (thymidine kinase), ORF60 (ribonucleotide reductase, small subunit), and cellular interleukin-10 (IL-10) contain a sequence motif similar to the Sp1/Sp3-binding region of the 56p-RE element, and we found that these promoters could also be synergistically activated by ORF50 and Sp3 via the conserved motifs. Noteworthily, the conversion of the Sp1/Sp3-binding sequence of the 56p-RE element into a consensus high-affinity Sp-binding sequence completely lost the synergistic response to ORF50 and Sp3. Moreover, transcriptional synergy could not be detected through other ORF50-responsive elements from the viral PAN, K12, ORF57, and K6 promoters. Collectively, the results of our study demonstrate that ORF50 and Sp3 can act in synergy on the transcription of specific gene promoters, and we find a novel conserved cis-acting motif in these promoters essential for transcriptional synergy.IMPORTANCE Despite the critical role of ORF50 in the KSHV latent-to-lytic switch, the molecular mechanism by which ORF50 activates its downstream target genes, especially those that encode the viral DNA replication enzymes, is not yet fully understood. Here, we find that ORF50 can cooperate with Sp3 to synergistically activate promoters of the viral ORF56 (primase), ORF21 (thymidine kinase), and ORF60 (ribonucleotide reductase) genes via similar Sp1/Sp3-binding motifs. Additionally, the same synergistic effect can be seen on the promoter of the cellular IL-10 gene. Overall, our data reveal an important role for Sp3 in ORF50-mediated transactivation, and we propose a new subclass of ORF50-responsive elements in viral and cellular promoters.


Subject(s)
Herpesvirus 8, Human/genetics , Immediate-Early Proteins/genetics , Promoter Regions, Genetic , Sp1 Transcription Factor/genetics , Sp3 Transcription Factor/genetics , Trans-Activators/genetics , Transcription, Genetic , Animals , Binding Sites , Cell Line , Cell Line, Tumor , Clone Cells , Fibroblasts/virology , Gene Expression Regulation , HEK293 Cells , Herpesvirus 8, Human/metabolism , Host-Pathogen Interactions/genetics , Humans , Immediate-Early Proteins/metabolism , Immunoglobulin J Recombination Signal Sequence-Binding Protein/genetics , Immunoglobulin J Recombination Signal Sequence-Binding Protein/metabolism , Interleukin-10/genetics , Interleukin-10/metabolism , Lymphocytes/virology , Mice , Protein Binding , Response Elements , Signal Transduction , Sp1 Transcription Factor/metabolism , Sp3 Transcription Factor/metabolism , Trans-Activators/metabolism , Viral Proteins/genetics , Viral Proteins/metabolism , Viral Regulatory and Accessory Proteins/genetics , Viral Regulatory and Accessory Proteins/metabolism
15.
Am J Clin Pathol ; 154(5): 635-644, 2020 10 13.
Article in English | MEDLINE | ID: mdl-32561911

ABSTRACT

OBJECTIVE: To explore the clinical and pathologic features of ovarian juvenile granulosa cell tumors (JGCTs). METHODS: Clinical data, histopathologic observations, immunohistochemical results, FOXL2 mutation status, and follow-up information of 7 JGCT cases were studied. RESULTS: The patients most commonly presented with abdominal distension and pain (5 cases), followed by precocious puberty (1 case) and a pelvic mass (1 case). Six patients had stage I disease, and 1 had stage IV disease. The microscopic examinations typically showed lobular growth punctuated by variably sized and shaped follicles. Rare features included a reticular-cystic appearance mimicking a yolk sac tumor (2 cases), a lobular appearance similar to a sclerosing stromal tumor (1 case), strands and cords (1 case), pseudopapillary appearance (2 cases), spindle cell appearance (1 case), microcystic appearance (1 case), hobnail cells (1 case), and rhabdomyoid cells (1 case). No FOXL2 mutation was encountered. After a median follow-up of 53 months, only 1 patient with a strongly diffuse TP53-positive tumor died of the disease, and 2 successfully had babies. CONCLUSIONS: JGCT is a rare neoplasm with a wide morphologic spectrum and is easily confused with other tumors. Familiarity with the characteristics, rare atypical appearances, and immunohistochemical results may aid in obtaining a correct diagnosis.


Subject(s)
Granulosa Cell Tumor/pathology , Ovarian Neoplasms/pathology , Ovary/pathology , Adult , Child , Female , Forkhead Transcription Factors/genetics , Granulosa Cell Tumor/genetics , Humans , Infant, Newborn , Mutation , Ovarian Neoplasms/genetics
16.
J Mol Histol ; 50(4): 369-374, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31190160

ABSTRACT

The first cell lineage differentiation occurs during the development of mouse 8-cell embryo to blastocyst. Akt is a potent kinase whose role during blastocyst formation has not been elucidated. In the present study, immunofluorescence results showed that the Akt protein was specifically localized to the outer cells of the morula. Akt-specific inhibitor MK2206 significantly inhibited mouse blastocyst formation and resulted in decreased expression of the trophectoderm marker Cdx2 and led to granular distribution of ERα in the cytoplasm. Furthermore, knockdown of ERα by siRNA microinjection can also lead to a decrease in the development rate of mouse blastocysts, accompanied by a decrease in the expression level of Yap protein. We conclude that Akt may be indispensable for the first cell lineage differentiation of mouse.


Subject(s)
Cell Differentiation , Cell Lineage , Embryo, Mammalian/cytology , Proto-Oncogene Proteins c-akt/physiology , Adaptor Proteins, Signal Transducing/metabolism , Animals , Blastocyst/cytology , Cell Cycle Proteins/metabolism , Embryonic Development , Gene Expression Regulation, Developmental , Mice , Morula/chemistry , YAP-Signaling Proteins
17.
Toxicol Appl Pharmacol ; 378: 114612, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31175881

ABSTRACT

Infertility caused by environmental pollution is becoming a global problem, but an effective prevention or treatment is lacking. Icariin (ICA) is a flavonoid used in traditional Chinese medicine. The present study investigated the possible roles of ICA in preventing testicular dysfunction caused by di(2-ethylhexyl) phthalate (DEHP), one of the most studied environmental endocrine disruptors. Cultured mouse Leydig cells were pretreated with ICA and exposed to DEHP to determine ICA effects upon cell proliferation, reactive oxygen species (ROS) levels, mitochondrial membrane potential (Δψm), testosterone levels and the expression of transcription factor SF-1 and steroidogenic enzymes (CYP11, 3ß-HSD and 17ß-HSD), which play critical roles in androgen production. Our results showed that ICA reversed the adverse effect of DEHP on Leydig cell proliferation, and decreased ROS levels and elevated Δψm levels. Also, ICA promoted testosterone production and up-regulated the expression of SF-1 and steroidogenic enzymes. We investigated ICA actions in vivo, using male mice administrated DEHP followed by ICA. Exposure to DEHP decreased epididymal sperm counts and disrupted seminiferous tubules, and both of these effects were reversed by ICA treatment. These results showed that the mechanisms of ICA in protecting mouse testes against DEHP-induced damage involves the prevention of ROS accumulation and promotion of testosterone secretion.


Subject(s)
Diethylhexyl Phthalate/adverse effects , Flavonoids/pharmacology , Leydig Cells/drug effects , Phthalic Acids/adverse effects , Protective Agents/pharmacology , Testosterone/metabolism , Animals , Cell Proliferation/drug effects , Endocrine Disruptors/metabolism , Female , Leydig Cells/metabolism , Male , Mice , Mice, Inbred ICR , Pregnancy , Prenatal Exposure Delayed Effects/metabolism , Reactive Oxygen Species/metabolism , Spermatozoa/drug effects , Spermatozoa/metabolism , Testis/drug effects , Testis/metabolism
18.
Cell Cycle ; 18(4): 437-451, 2019 02.
Article in English | MEDLINE | ID: mdl-30712485

ABSTRACT

Zygotic genome activation (ZGA) is one of the most critical events at the beginning of mammalian preimplantation embryo development (PED). The mechanisms underlying mouse ZGA remain unclear although it has been widely studied. In the present study, we identified that tricho-rhino-phalangeal syndrome 1 (TRPS1), an atypical GATA family member, is an important factor for ZGA in mouse PED. We found that the Trps1 mRNA level peaked at the one-cell stage while TRPS1 protein did so at the two/four-cell stage. Knockdown of Trps1 by the microinjection of Trps1 siRNA reduced the developmental rate of mouse preimplantation embryos by approximately 30%, and increased the expression of ZGA marker genes MuERV-L and Zscan4d via suppressing the expression of major histone markers H3K4me3 and H3K27me3. Furthermore, Trps1 knockdown decreased the expression of Sox2 but increased Oct4 expression. We conclude that TRPS1 may be indispensable for zygotic genome activation during mouse PED.


Subject(s)
Blastocyst/metabolism , Embryonic Development/genetics , Repressor Proteins/genetics , Repressor Proteins/metabolism , Zygote/metabolism , Animals , Female , Gene Expression Regulation, Developmental , Gene Knockdown Techniques , Histones/genetics , Male , Mice , Microinjections , Octamer Transcription Factor-3/metabolism , Proteins/genetics , RNA, Messenger/genetics , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/pharmacology , SOXB1 Transcription Factors/metabolism , Transcription Factors/genetics , Transcriptional Activation/genetics
19.
Virus Res ; 256: 76-89, 2018 09 02.
Article in English | MEDLINE | ID: mdl-30096410

ABSTRACT

The BKRF2, BKRF3 and BKRF4 genes of Epstein-Barr virus (EBV) are located close together in the viral genome, which encode glycoprotein L, uracil-DNA glycosylase and a tegument protein, respectively. Here, we demonstrate that the BKRF2 gene behaves as a true-late lytic gene, whereas the BKRF3 and BKRF4 genes belong to the early lytic gene family. Our results further reveal that both BKRF3 and BKRF4 promoters are new synergistic targets of Zta and Rta, two EBV latent-to-lytic switch transactivators. Multiple Rta- and Zta-responsive elements within the BKRF3 and BKRF4 promoters were identified and characterized experimentally. Importantly, we show that DNA methylation is absolutely required for activation of the BKRF4 promoter by Zta alone or in combination with Rta. Moreover, we find that sodium butyrate, an inducing agent of EBV reactivation, is capable of activating the BKRF4 promoter through a mechanism independent of Zta and Rta. Overall, our studies highlight the complexity of transcriptional regulation of lytic genes within the BKRF2-BKRF3-BKRF4 gene locus.


Subject(s)
Gene Expression Regulation, Viral , Herpesvirus 4, Human/growth & development , Herpesvirus 4, Human/genetics , Membrane Glycoproteins/genetics , Molecular Chaperones/genetics , Uracil-DNA Glycosidase/genetics , Viral Proteins/genetics , DNA Methylation , DNA, Viral/metabolism , Gene Expression Profiling , Immediate-Early Proteins/metabolism , Promoter Regions, Genetic , Protein Binding , Trans-Activators/metabolism
20.
Sensors (Basel) ; 18(7)2018 Jun 25.
Article in English | MEDLINE | ID: mdl-29941793

ABSTRACT

In many Internet of Things (IoT) applications, large numbers of small sensor data are delivered in the network, which may cause heavy traffics. To reduce the number of messages delivered from the sensor devices to the IoT server, a promising approach is to aggregate several small IoT messages into a large packet before they are delivered through the network. When the packets arrive at the destination, they are disaggregated into the original IoT messages. In the existing solutions, packet aggregation/disaggregation is performed by software at the server, which results in long delays and low throughputs. To resolve the above issue, this paper utilizes the programmable Software Defined Networking (SDN) switch to program quick packet aggregation and disaggregation. Specifically, we consider the Programming Protocol-Independent Packet Processor (P4) technology. We design and develop novel P4 programs for aggregation and disaggregation in commercial P4 switches. Our study indicates that packet aggregation can be achieved in a P4 switch with its line rate (without extra packet processing cost). On the other hand, to disaggregate a packet that combines N IoT messages, the processing time is about the same as processing N individual IoT messages. Our implementation conducts IoT message aggregation at the highest bit rate (100 Gbps) that has not been found in the literature. We further propose to provide a small buffer in the P4 switch to significantly reduce the processing power for disaggregating a packet.

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