RESUMO
Coronaviruses target ciliate cells causing the loss of cilia, acute rhinorrheas, and other ciliopathies. The loss of ciliary function may help the virus infect, replicate, and spread. However, the molecular mechanisms by which coronaviruses cause ciliary defects are still unclear. Herein we demonstrate how coronavirus infection and severe acute respiratory syndrome coronavirus2 3CL protease induce cilia dysfunction by targeting a host protein septin that is required for the structure and function of cilia. Further, we demonstrate that coronaviruses and 3CL protease lead to the cleavage of several septin proteins (SEPT2, -6, and -9), producing cleaved obstructive fragments. Furthermore, ectopic expression of cleaved SEPT2 fragments shows defective ciliogenesis, disoriented septin filaments, and ablated Sonic Hedgehog (SHH) signaling in a protease activity-dependent manner. We present that the 3CLpro inhibitors are potent and prevent abnormal ciliary structures and SHH signaling. These results provide useful insights into the general mechanisms underlying ciliary defects caused by coronaviruses, which, in turn, facilitate virus spread and prove that preclinical and clinical 3CL protease inhibitors may prove useful as therapeutics for treating ciliary defects of coronaviruses.
Assuntos
COVID-19 , Septinas , Humanos , Septinas/genética , Septinas/metabolismo , Proteínas Hedgehog/metabolismo , Peptídeo Hidrolases/metabolismo , Transdução de Sinais , Endopeptidases/metabolismo , Inibidores de Proteases/uso terapêuticoRESUMO
Store-operated Ca2+ entry (SOCE) is a major Ca2+ influx pathway that is controlled by the ER Ca2+ sensor STIM1. Abnormal activation of STIM1 directly influences Ca2+ influx, resulting in severe diseases such as Stormorken syndrome. The inactivation domain of STIM1 (IDstim) has been identified as being essential for Ca2+-dependent inactivation of STIM1 (CDI) after SOCE occurs. However, it is unknown whether IDstim is involved in keeping STIM1 inactive before CDI. Herein, we show that IDstim helps STIM1 keep inactive through intramolecular binding with the coiled-coil domain. Between IDstim and the coiled-coil domain, we found a short conserved linker whose extension or mutation leads to the constitutive activation of STIM1. We have demonstrated that IDstim needs the coiled-coil domain 1 (CC1) to inhibit the Ca2+ release-activated Ca2+ (CRAC) activation domain (CAD) activity and binds to a CC1-CAD fragment. Serial deletion of CC1 revealed that CC1α1 is a co-inhibitory domain of IDstim. CC1α1 deletion or leucine mutation, which abolishes the closed conformation, impaired the inhibitory effect and binding of IDstim. These results suggest that IDstim cooperates with CC1α1 to help STIM1 keep inactive under resting conditions.
Assuntos
Proteínas de Neoplasias/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Cálcio/metabolismo , Células HEK293 , Humanos , Conformação Proteica , Domínios ProteicosRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that has caused a 'coronavirus disease 2019' (COVID-19) pandemic in multiple waves, which threatens human health and public safety. During this pandemic, some patients with COVID-19 acquired secondary infections, such as mucormycosis, also known as black fungus disease. Mucormycosis is a serious, acute, and deadly fungal infection caused by Mucorales-related fungal species, and it spreads rapidly. Hence, prompt diagnosis and treatment are necessary to avoid high mortality and morbidity rates. Major risk factors for this disease include uncontrolled diabetes mellitus and immunosuppression that can also facilitate increases in mucormycosis infections. The extensive use of steroids to prevent the worsening of COVID-19 can lead to black fungus infection. Generally, antifungal agents dedicated to medical applications must be biocompatible, non-toxic, easily soluble, efficient, and hypoallergenic. They should also provide long-term protection against fungal growth. COVID-19-related black fungus infection causes a severe increase in fatalities. Therefore, there is a strong need for the development of novel and efficient antimicrobial agents. Recently, nanoparticle-containing products available in the market have been used as antimicrobial agents to prevent bacterial growth, but little is known about their efficacy with respect to preventing fungal growth, especially black fungus. The present review focuses on the effect of various types of metal nanoparticles, specifically those containing silver, zinc oxide, gold, copper, titanium, magnetic, iron, and carbon, on the growth of various types of fungi. We particularly focused on how these nanoparticles can impact the growth of black fungus. We also discussed black fungus co-infection in the context of the global COVID-19 outbreak, and management and guidelines to help control COVID-19-associated black fungus infection. Finally, this review aimed to elucidate the relationship between COVID-19 and mucormycosis.
Assuntos
Tratamento Farmacológico da COVID-19 , Mucorales , Mucormicose , Nanopartículas , Óxido de Zinco , Humanos , SARS-CoV-2 , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Mucormicose/tratamento farmacológico , Mucormicose/epidemiologia , Mucormicose/microbiologia , Prata/farmacologia , Óxido de Zinco/farmacologia , Cobre/farmacologia , Titânio/farmacologia , Ferro/farmacologia , Ouro/farmacologia , Carbono/farmacologiaRESUMO
Store-operated calcium entry (SOCE), an important mechanism of Ca2+ signaling in a wide range of cell types, is mediated by stromal interaction molecule (STIM), which senses the depletion of endoplasmic reticulum Ca2+ stores and binds and activates Orai channels in the plasma membrane. This inside-out mechanism of Ca2+ signaling raises an interesting question about the evolution of SOCE: How did these two proteins existing in different cellular compartments evolve to interact with each other? We investigated the gating mechanism of Caenorhabditis elegans Orai channels. Our analysis revealed a mechanism of Orai gating by STIM binding to the intracellular 2-3 loop of Orai in C. elegans that is radically different from Orai gating by STIM binding to the N and C termini of Orai in mammals. In addition, we found that the conserved hydrophobic amino acids in the 2-3 loop of Orai1 are important for the oligomerization and gating of channels and are regulated via an intramolecular interaction mechanism mediated by the N and C termini of Orai1. This study identifies a previously unknown SOCE mechanism in C. elegans and suggests that, while the STIM-Orai interaction is conserved between invertebrates and mammals, the gating mechanism for Orai channels differs considerably.
Assuntos
Caenorhabditis elegans/metabolismo , Canais de Cálcio/metabolismo , Cálcio/metabolismo , Ativação do Canal Iônico , Proteína ORAI1/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Sequência de Aminoácidos , Animais , Caenorhabditis elegans/genética , Canais de Cálcio/química , Canais de Cálcio/genética , Sinalização do Cálcio , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Evolução Molecular , Células HEK293 , Humanos , Proteína ORAI1/química , Proteína ORAI1/genética , Homologia de Sequência , Molécula 1 de Interação Estromal/química , Molécula 1 de Interação Estromal/genéticaRESUMO
Terpenoids are the most diverse natural products with many industrial applications and are all synthesized from simple precursors, isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). In plants, IPP is synthesized by two distinct metabolic pathways - cytosolic mevalonate (MVA) pathway for C15 sesquiterpene and C30 triterpene, and plastidic methylerythritol phosphate (MEP) pathway for C10 monoterpene and C20 diterpene. A number of studies have altered the metabolic gene expressions in either the MVA or MEP pathway to increase terpene production; however, it remains unknown if the alteration of the acetyl-CoA pool in plastid fatty acid biosynthesis can influence terpenoid flux. Here, we focused on the fact that acetyl-CoA is the precursor for both fatty acid biosynthesis in plastid and terpene biosynthesis in cytosol, and the metabolic impact of increased plastidic acetyl-CoA level on the cytosolic terpene biosynthesis was investigated. In tobacco leaf infiltration studies, the acetyl-CoA carboxylase complex (the enzyme supplying malonyl-CoA in plastid) was partially inhibited by overexpressing the inactive form of biotin carboxyl carrier protein (BCCP) by a negative dominant effect. Overexpression of BCCP showed 1.4-2.4-fold increase of sesquiterpenes in cytosol; however, surprisingly overexpression of BCCP linked to truncated HMG-CoA reductase (tHMGR) by a cleavable peptide 2A showed 20-40-fold increases of C15 sesquiterpenes (α-bisabolol, amorphadiene, and valerenadiene) and a 6-fold increase of C30 ß-amyrin. α-Bisabolol and ß-amyrin production reached 28.8â¯mgâ¯g-1 and 9.8â¯mgâ¯g-1 dry weight, respectively. Detailed analyses showed that a large increase in flux was achieved by the additive effect of BCCP- and tHMGR-overexpression, and an enhanced tHMGR activity by 2A peptide tag. Kinetic analyses showed that tHMGR-2A has a three-fold higher kcat value than tHMGR. The tHMGR-2A-BCCP1 co-expression strategy in this work provides a new insight into metabolic cross-talks and can be a generally applicable approach to over-produce sesqui- and tri-terpene in plants.
Assuntos
Acetil-CoA Carboxilase/metabolismo , Proteínas de Transporte/metabolismo , Hidroximetilglutaril-CoA Redutases/metabolismo , Nicotiana/metabolismo , Sesquiterpenos/metabolismo , Triterpenos/metabolismo , Acetilcoenzima A/metabolismo , Citosol/metabolismo , Ácido Graxo Sintase Tipo II/metabolismo , Ácidos Graxos/biossíntese , Hidroximetilglutaril-CoA Redutases/genética , Malonil Coenzima A/metabolismo , Sesquiterpenos Monocíclicos , Folhas de Planta/metabolismo , Nicotiana/genéticaRESUMO
To identify terpene synthases (TPS) responsible for the biosynthesis of the sesquiterpenes that contribute to the characteristic flavors of black pepper (Piper nigrum), unripe peppercorn was subjected to the Illumina transcriptome sequencing. The BLAST analysis using amorpha-4,11-diene synthase as a query identified 19 sesquiterpene synthases (sesqui-TPSs), of which three full-length cDNAs (PnTPS1 through 3) were cloned. These sesqui-TPS cDNAs were expressed in E. coli to produce recombinant enzymes for in vitro assays, and also expressed in the engineered yeast strain to assess their catalytic activities in vivo. PnTPS1 produced ß-caryophyllene as a main product and humulene as a minor compound, and thus was named caryophyllene synthase (PnCPS). Likewise, PnTPS2 and PnTPS3 were, respectively, named cadinol/cadinene synthase (PnCO/CDS) and germacrene D synthase (PnGDS). PnGDS expression in yeast yielded ß-cadinene and α-copaene, the rearrangement products of germacrene D. Their kcat/Km values (20-37.7â¯s-1â¯mM-1) were comparable to those of other sesqui-TPSs. Among three PnTPSs, the transcript level of PnCPS was the highest, correlating with the predominant ß-caryophyllene biosynthesis in the peppercorn. The products and rearranged products of three PnTPSs could account for about a half of the sesquiterpenes in number found in unripe peppercorn.
Assuntos
Alquil e Aril Transferases , Clonagem Molecular , Frutas , Piper nigrum , Proteínas de Plantas , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , DNA Complementar/genética , Frutas/enzimologia , Frutas/genética , Sesquiterpenos Monocíclicos , Piper nigrum/enzimologia , Piper nigrum/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sesquiterpenos Policíclicos , Sesquiterpenos/metabolismoRESUMO
Colorectal cancer (CRC) is one of the most common cancers and has a high rate of morbidity and mortality worldwide. Very-low-density-lipoprotein receptor (VLDLR), a member of the low-density-lipoprotein receptor (LDLR) superfamily, is a multifunctional receptor that regulates cellular signaling by binding numerous ligands. Several studies reported the altered expression of VLDLR and suggested that VLDLR may play a critical role in tumor development by affecting cell proliferation and metastasis. However, the function of VLDLR and regulation of its expression by miRNAs have not been investigated in CRC. In the present study, we investigated the expression of VLDLR in CRC patients and found it to be significantly decreased in tumors in comparison with paired adjacent non-tumor tissues. Moreover, VLDLR over-expression inhibited the proliferation and migration of CRC cells. We also found that VLDLR expression was negatively regulated by miR-200c in CRC cells and that their expression levels were inversely correlated in CRC patients. These data suggest that VLDLR down-regulation mediated by the increased expression of miR-200c may be involved in the development of CRC.
Assuntos
Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Receptores de LDL/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Colo/metabolismo , Colo/patologia , Neoplasias Colorretais/patologia , Regulação para Baixo , Humanos , Reto/metabolismo , Reto/patologiaRESUMO
OBJECTIVE: The aim of this study is to investigate the behaviour of iPSc derived from dental stem cells in terms of initial adhesion, differentiation potential on differently surface-treated titanium disc. MATERIALS AND METHODS: iPSc derived from human gingival fibroblasts (hGFs) were established using 4-reprogramming factors transduction with Sendai virus. The hGF-iPSc established in this study exhibited the morphology and growth properties similar to human embryonic stem (ES) cells and expressed pluripotency makers. Alkaline Phosphatase (AP) staining, Embryoid Body (EB) formation and in vitro differentiation and karyotyping further confirmed pluripotency of hGF-iPSc. Then, hGF-iPSc were cultured on machined- and Sandblasted and acid etched (SLA)-treated titanium discs with osteogenic induction medium and their morphological as well as quantitative changes according to different surface types were investigated using Alizrin Red S staining, Scanning electron microscopy (SEM), Flow cytometry and RT-PCR. RESULTS: Time-dependent and surface-dependent morphological changes as well as quantitative change in osteogenic differentiation of hGF-iPSc were identified and osteogenic gene expression of hGF-iPSc cultured on SLA-treated titanium disc found to be greater than machined titanium disc, suggesting the fate of hGF-iPSc may be determined by the characteristics of surface to which hGF-iPSc first adhere. CONCLUSIONS: iPSc derived from dental stem cell can be one of the most promising and practical cell sources for personalized regenerative dentistry and their morphological change as well as quantitative change in osteogenic differentiation according to different surface types may be further utilized for future clinical application incorporated with dental implant.
Assuntos
Fibroblastos/fisiologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Implantes Dentários , Gengiva/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Osteogênese , Propriedades de Superfície , Titânio/farmacologiaRESUMO
PURPOSE: This study evaluates the synergistic effect of serial application of bone morphogenetic protein 2 (BMP2) and fibroblast growth factor 2 (FGF2) on both new bone formation and periodontal tissue regeneration using 1-wall intrabony defect in mongrel dogs. MATERIALS AND METHODS: One-wall defects were created at the mesial aspect of the mandibular first molars of 6 male mongrel dogs. Each mandibular defect received 1 of the 2 experimental treatments randomly (BMP2 or BMP2 + FGF2), and it was allowed to heal for either 4 or 8 weeks postoperatively. Histologic and histomorphometric analyses were performed for the evaluation of the overall healing patterns of new bone formation and periodontal tissue regeneration. RESULTS: The results showed that after 8 weeks, serial application of BMP2 and FGF2 significantly improved the periodontal tissue regeneration, whereas application of BMP2 only showed greater new bone formation after 4 weeks. CONCLUSIONS: The serial application of BMP2 and FGF2 may have synergistic effects on periodontal tissue regeneration over time.
Assuntos
Proteína Morfogenética Óssea 2/uso terapêutico , Fator 2 de Crescimento de Fibroblastos/uso terapêutico , Regeneração Tecidual Guiada Periodontal/métodos , Animais , Proteína Morfogenética Óssea 2/administração & dosagem , Regeneração Óssea/efeitos dos fármacos , Cães , Sinergismo Farmacológico , Fator 2 de Crescimento de Fibroblastos/administração & dosagem , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/patologia , Periodonto/diagnóstico por imagem , Periodonto/patologia , Microtomografia por Raio-XRESUMO
Marine red macroalgae have emerged to be renewable biomass for the production of chemicals and biofuels, because carbohydrates that form the major component of red macroalgae can be hydrolyzed into fermentable sugars. The main carbohydrate in red algae is agarose, and it is composed of D-galactose and 3,6-anhydro-L-galactose (AHG), which are alternately bonded by ß1-4 and α1-3 linkages. In this study, a novel ß-galactosidase that can act on agarooligosaccharides (AOSs) to release galactose was discovered in a marine bacterium (Vibrio sp. strain EJY3); the enzyme is annotated as Vibrio sp. EJY3 agarolytic ß-galactosidase (VejABG). Unlike the lacZ-encoded ß-galactosidase from Escherichia coli, VejABG does not hydrolyze common substrates like lactose and can act only on the galactose moiety at the nonreducing end of AOS. The optimum pH and temperature of VejABG on an agarotriose substrate were 7 and 35°C, respectively. Its catalytic efficiency with agarotriose was also similar to that with agaropentaose or agaroheptaose. Since agarotriose lingers as the unreacted residual oligomer in the currently available saccharification system using ß-agarases and acid prehydrolysis, the agarotriose-hydrolyzing capability of this novel ß-galactosidase offers an enormous advantage in the saccharification of agarose or agar in red macroalgae for its use as a biomass feedstock for fermentable sugar production.
Assuntos
Ágar/metabolismo , Sefarose/metabolismo , Vibrio/enzimologia , beta-Galactosidase/metabolismo , Ágar/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Metabolismo dos Carboidratos , Carboidratos/química , Clonagem Molecular , Fermentação , Galactose/química , Galactose/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Filogenia , Rodófitas/química , Especificidade por Substrato , Temperatura , Vibrio/genética , beta-Galactosidase/genéticaRESUMO
BACKGROUND: A postovulatory mammalian oocyte decreases developmental potential with in vivo aging in the oviduct or in vitro aging in the culture dish. The mechanism underlying oocyte aging still largely remains an enigma. Accumulating data suggest that the epigenetic alterations such as histone acetylation are also associated with postovulatory aging. OBJECTIVE: To perform a review evaluating a new aspect of oocyte aging in terms of the epigenetic alterations focusing on lysine acetylation. METHODS: In addition to a search of the literature in Pubmed, we introduced our recent published data. RESULTS: Histone acetylation in the mouse oocyte increases during aging, potentially impacting gene regulation in the subsequent embryonic development. Oocyte aging results in increased acetylation of alpha-tubulin, a non-histone protein, and nicotinamide, an inhibitor of class III HDAC, partially prevents some of oocyte aging phenotypes. CONCLUSION: Abnormal regulation of protein acetylation itself is suggested in oocyte aging and could contribute to the aging phenotypes.
RESUMO
OBJECTIVES: Adult child socioeconomic status (SES) has been identified as a predictor of older parents' cognitive aging. However, studies have primarily relied on educational attainment as the sole measure of adult child SES. We evaluated the relationship between adult children's financial disadvantage and cognitive outcomes of older parents in the United States. METHODS: We used data from U.S. Health and Retirement Study (2000-2014, n = 15,053 respondents ≥51 years with at least 1 adult child). Adult child financial disadvantage was measured with 3 indicators of extremely low income, unemployment, and lack of homeownership. We used linear mixed models to estimate the association between adult child financial disadvantage and the rate of decline in verbal memory scores, controlling for respondents' sociodemographic characteristics. RESULTS: Having at least 1 adult child (vs no adult children) with extremely low income was found to be associated with lower verbal memory (b = -0.041, 95% confidence interval [CI]: -0.043, -0.039) at baseline. There was a small but significant association with the rate of decline in verbal memory z-scores (b = 0.004, 95% CI: 0.000, 0.008) and some evidence of heterogeneity by parent gender, marital status, and SES. DISCUSSION: Offspring financial disadvantage may be influential for older parents' initial level of memory function, although evidence of associations with memory decline was weak. Public policy interventions aimed at improving the economic conditions of adult children may indirectly benefit the cognitive performance of disadvantaged parents in their later life.
Assuntos
Filhos Adultos , Pais , Humanos , Masculino , Feminino , Estados Unidos , Idoso , Filhos Adultos/psicologia , Filhos Adultos/estatística & dados numéricos , Pessoa de Meia-Idade , Pais/psicologia , Classe Social , Envelhecimento Cognitivo/psicologia , Pobreza/estatística & dados numéricos , Pobreza/psicologia , Disfunção Cognitiva/epidemiologia , Renda/estatística & dados numéricos , Desemprego/estatística & dados numéricos , Desemprego/psicologiaRESUMO
OBJECTIVE: To test whether the impacts of Medicaid's Home and Community-Based Services (HCBS) expenditures have been equitable. DATA SOURCES AND STUDY SETTING: This is a secondary data analysis. We linked annual data on state-level Medicaid HCBS expenditures with individual data from U.S. Health and Retirement Study (HRS; 2006-2016). STUDY DESIGN: We evaluated the association between state-level HCBS expenditure quartiles and the risk of experiencing challenges in basic or instrumental activities of daily living (I/ADLs) without assistance (unmet needs for care). We fitted generalized estimating equations (GEE) with a Poisson distribution, log link function, and an unstructured covariance matrix. We controlled demographics, time, and place-based fixed effects and estimated models stratified by race and ethnicity, gender, and urbanicity. We tested the robustness of results with negative controls. DATA COLLECTION/EXTRACTION METHODS: Our analytic sample included HRS Medicaid beneficiaries, aged 55+, who had difficulty with ≥1 I/ADL (n = 2607 unique respondents contributing 4719 person-wave observations). PRINCIPAL FINDINGS: Among adults with IADL difficulty, higher quartiles of HCBS expenditure (vs. the lowest quartile) were associated with a lower overall prevalence of unmet needs for care (e.g., Prevalence Ratio [PR], Q4 vs. Q1: 0.91, 95% CI: 0.84-0.98). This protective association was concentrated among non-Hispanic white respondents (Q4 vs. Q1: 0.82, 95% CI: 0.73-0.93); estimates were imprecise for Hispanic individuals and largely null for non-Hispanic Black participants. We found no evidence of heterogeneity by gender or urbanicity. Negative control robustness checks indicated that higher quartiles of HCBS expenditure were not associated with (1) the risk of reporting I/ADL difficulty among 55+ Medicaid beneficiaries, and (2) the risk of unmet care needs among non-Medicaid beneficiaries. CONCLUSION: The returns to higher state-level HCBS expenditures under Medicaid for older adults with I/ADL disability do not appear to have been equitable by race and ethnicity.
Assuntos
Gastos em Saúde , Serviços de Assistência Domiciliar , Humanos , Estados Unidos , Idoso , Serviços de Saúde Comunitária , Atividades Cotidianas , MedicaidRESUMO
Previous studies show that treatment of zygotes with trichostatin A (TSA), a histone deacetylase inhibitor (HDACi), impacts the subsequent development to a blastocyst as well as full-term development. To reveal the dynamics of protein acetylation, with and without TSA treatment during one-cell stage, we examined oocytes and zygotes by immunofluorescence and Western Blot analyses using anti-acetylated lysine and acetylated α-tubulin antibodies. In unfertilized oocytes, lysine acetylation level was extremely low over all but faintly detected in the spindle. Once oocyte activation occurs, a dramatic increase of lysine acetylation signal was observed mostly in the pronuclei and a fiber-like structure, the so called midbody, suggesting activation coupled up-regulation of lysine acetylation presumably in histones and α-tubulin. TSA treatment resulted in significantly more hyperacetylation not only in the midbody structure and pronuclei but also in the whole cytoplasm. Consistently, Western Blot analysis revealed that acetylation of proteins about 53 kDa and 11 kDa in size, corresponding to α-tubulin and histone H4 sizes respectively, were increased mainly after oocyte activation and exclusively enhanced by TSA treatment in zygotes. To confirm this behavior of acetylated nonhistone proteins, acetylated α-tubulin was examined and found to be faintly detected in the spindle of MII oocytes but later in whole in the cell of zygotes including the midbody, which was enhanced by TSA treatment. To elucidate the mechanism underlying up-regulation of lysine acetylation following oocyte activation, we assayed the HDAC activity, and found significant reduction of HDAC activity from MII to zygotic stages. Taken together, our data indicate that HDACs play an important role in maintaining low acetylated status in a MII oocyte. However, once an oocyte has been activated, histone and nonhistone proteins including α-tubulin are hyperacetylated partly due to a reduction of HDAC activity. TSA treatment of zygotes enhances their acetylation, which could affect subsequent embryonic development.
Assuntos
Lisina/metabolismo , Regulação para Cima , Acetilação/efeitos dos fármacos , Animais , Feminino , Fertilização in vitro , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Regulação para Cima/efeitos dos fármacos , Zigoto/efeitos dos fármacos , Zigoto/metabolismoRESUMO
Postovulatory mammalian oocyte developmental potential decreases with aging in vivo and in vitro. Aging oocytes typically show cellular fragmentation and chromosome scattering with an abnormally shaped spindle over time. Previously, it was shown that histone acetylation in the mouse oocyte increased during aging and that treatment with trichostatin A (TSA), an inhibitor for class I and II histone deacetylases (HDACs), enhanced the acetylation, that is, aging. In this study, we examined the effect of nicotinamide (NAM), an inhibitor for class III HDACs, on in vitro aging of mouse oocytes as well as TSA. We found that treatment with NAM significantly inhibited cellular fragmentation, spindle elongation and astral microtubules up to 48 h of culture. Although presence of TSA partially inhibited cellular fragmentation and spindle elongation up to 36 h of culture, treatment with TSA induced chromosome scattering at 24 h of culture and more severe cellular fragmentation at 48 h of culture. Further, we found that α-tubulin, a nonhistone protein, increased acetylation during aging, suggesting that not only histone but nonhistone protein acetylation may also increase with oocyte aging. Thus, these data indicate that protein acetylation is abnormally regulated in aging oocytes, which are associated with a variety of aging phenotypes, and that class I/II and class III HDACs may play distinct roles in aging oocytes.
Assuntos
Senescência Celular/efeitos dos fármacos , Inibidores de Histona Desacetilases/química , Histona Desacetilases/metabolismo , Niacinamida/química , Oócitos/efeitos dos fármacos , Animais , Apoptose , Cromossomos/ultraestrutura , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Histonas/química , Ácidos Hidroxâmicos/química , Camundongos , Microtúbulos/metabolismo , Estresse Oxidativo , Fenótipo , Fuso Acromático/metabolismo , Fatores de Tempo , Tubulina (Proteína)/metabolismoRESUMO
Entosis is a non-apoptotic cell death process that forms characteristic cell-in-cell structures in cancers, killing invading cells. Intracellular Ca2+ dynamics are essential for cellular processes, including actomyosin contractility, migration, and autophagy. However, the significance of Ca2+ and Ca2+ channels participating in entosis is unclear. Here, it is shown that intracellular Ca2+ signaling regulates entosis via SEPTIN-Orai1-Ca2+ /CaM-MLCK-actomyosin axis. Intracellular Ca2+ oscillations in entotic cells show spatiotemporal variations during engulfment, mediated by Orai1 Ca2+ channels in plasma membranes. SEPTIN controlled polarized distribution of Orai1 for local MLCK activation, resulting in MLC phosphorylation and actomyosin contraction, leads to internalization of invasive cells. Ca2+ chelators and SEPTIN, Orai1, and MLCK inhibitors suppress entosis. This study identifies potential targets for treating entosis-associated tumors, showing that Orai1 is an entotic Ca2+ channel that provides essential Ca2+ signaling and sheds light on the molecular mechanism underlying entosis that involves SEPTIN filaments, Orai1, and MLCK.
Assuntos
Actomiosina , Neoplasias , Humanos , Entose/fisiologia , Septinas , Neoplasias/patologia , Morte Celular , Proteína ORAI1RESUMO
γδ T cells are a rare and unique prototype of T cells that share properties with natural killer cells in secondary lymphoid organs. Although many studies have revealed the function and importance of adult-derived γδ T cells in cancer biology and regenerative medicine, the low numbers of these cells hamper their application as therapeutic cell sources in the clinic. To solve this problem, pluripotent stem cell-derived γδ T cells are considered alternative cell sources; however, few studies have reported the generation of human pluripotent stem cell-derived γδ T cells. In the present study, we investigated whether lymphoid lineage γδ T cells were successfully generated from human pluripotent stem cells via hemogenic endothelium under defined culture conditions. Our results revealed that pluripotent stem cells successfully generated γδ T cells with an overall increase in transcriptional activity of lymphoid lineage genes and cytolytic factors, indicating the importance of the optimization of culture conditions in generating lymphoid lineage γδ T cells. We uncovered an initial step in differentiating γδ T cells that could be applied to basic and translational investigations in the field of cancer biology. Based on our result, we will develop an appropriate method to purify γδ T cells with functionality and it helpful for the study of basic mechanism of γδ T cells in pathophysiologic condition as well as clinic application.
RESUMO
Although it is known that the tetraploid embryo contributes only to the placenta, the question of why tetraploid embryos differentiate into placenta remains unclear. To study the effect of electrofusion on the development of mouse tetraploid oocytes, mouse two-cell embryos were fused and cultured in vitro in Chatot-Ziomek-Bavister medium. After electrofusion, two chromosome sets from the tetraploid blastomere were individually duplicated before nuclear fusion. At 8-10 hr after electrofusion, each chromosome set was condensing and the nuclear membrane was breaking down. Around 12-14 hr after electrofusion, the two chromosome sets had combined together and had reached the second mitotic metaphase, at this point with 8n sets of chromosomes. Interestingly, we discovered that expression of OCT4, an inner cell mass cells biomarker, is lost by the tetraploid expanded blastocysts, but that CDX2, a trophectoderm cells biomarker, is strongly expressed at this stage. This observation provides evidence clarifying why tetraploid embryos contribute only to trophectoderm.
Assuntos
Blastocisto/metabolismo , Cromossomos/metabolismo , Desenvolvimento Embrionário/fisiologia , Tetraploidia , Animais , Blastocisto/citologia , Fator de Transcrição CDX2 , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Desenvolvimento Embrionário/genética , Feminino , Proteínas de Homeodomínio/metabolismo , Cariotipagem , Masculino , Camundongos , Fator 3 de Transcrição de Octâmero/metabolismo , Gravidez , Fatores de Transcrição/metabolismoRESUMO
Progesterone receptor membrane component 1 (PGRMC1), the overexpression of which reduces survivability of cancer patients, is essential for cell migration and metastasis. However, the intracellular signaling pathways involved are largely unknown. Here, we report that PGRMC1 promotes store-operated Ca2+ entry (SOCE) as a functional interactor of stromal interaction molecule 1 (STIM1). PGRMC1 was repeatedly detected as an interactor of STIM1-Orai1 complex via complementation-dependent in situ labeling. Genetic depletion of PGRMC1 decreased SOCE and impaired activation of the nuclear factor of the activated T cell (NFAT) pathway. Mechanistically, PGRMC1 directly bound to the coiled-coil domain of STIM1, promoting STIM1 conformational switch. In breast cancer cells, PGRMC1 depletion reduced epidermal growth factor (EGF)-induced SOCE and disrupted focal adhesion turnover and actomyosin formation. These findings identify PGRMC1 as an essential regulator of Ca2+ signaling in breast cancer cells, providing a target for treating cancer metastasis and an insight for dissecting various PGRMC1/SOCE-induced biological processes.
Assuntos
Actomiosina/metabolismo , Neoplasias da Mama/patologia , Cálcio/metabolismo , Adesões Focais/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Receptores de Progesterona/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Neoplasias da Mama/metabolismo , Sinalização do Cálcio/fisiologia , Linhagem Celular , Humanos , Proteína ORAI1/metabolismo , Transdução de Sinais/fisiologiaRESUMO
OBJECTIVES: The genetic instability and DNA damage arise during transcription factor-mediated reprogramming of somatic cells, and its efficiency may be reduced due to abnormal chromatin remodelling. The efficiency in somatic cell nuclear transfer (SCNT)-mediated reprogramming is also very low, and it is caused by development arrest of most reconstituted embryos. MATERIALS AND METHODS: Whether the repair of genetic instability or double-strand breaks (DSBs) during SCNT reprogramming may play an important role in embryonic development, we observed and analysed the effect of Rad 51, a key modulator of DNA damage response (DDR) in SCNT-derived embryos. RESULTS: Here, we observed that the activity of Rad 51 is lower in SCNT eggs than in conventional IVF and found a significantly lower level of DSBs in SCNT embryos during reprogramming. To address this difference, supplementation with RS-1, an activator of Rad51, during the activation of SCNT embryos can increase RAD51 expression and DSB foci and thereby increased the efficiency of SCNT reprogramming. Through subsequent single-cell RNA-seq analysis, we observed the reactivation of a large number of genes that were not expressed in SCNT-2-cell embryos by the upregulation of DDR, which may be related to overcoming the developmental block. Additionally, there may be an independent pathway involving histone demethylase that can reduce reprograming-resistance regions. CONCLUSIONS: This technology can contribute to the production of comparable cell sources for regenerative medicine.