RESUMEN
Over the past few decades, significant improvements in maize yield have been largely attributed to increased plant density of upright hybrid varieties rather than increased yield per plant. However, dense planting triggers shade avoidance responses (SARs) that optimize light absorption but impair plant vigor and performance, limiting yield improvement through increasing plant density. In this study, we demonstrated that high-density-induced leaf angle narrowing and stem/stalk elongation are largely dependent on phytochrome B (phyB1/B2), the primary photoreceptor responsible for perceiving red (R) and far-red (FR) light in maize. We found that maize phyB physically interacts with the LIGULELESS1 (LG1), a classical key regulator of leaf angle, to coordinately regulate plant architecture and density tolerance. The abundance of LG1 is significantly increased by phyB under high R:FR light (low density) but rapidly decreases under low R:FR light (high density), correlating with variations in leaf angle and plant height under various densities. In addition, we identified the homeobox transcription factor HB53 as a target co-repressed by both phyB and LG1 but rapidly induced by canopy shade. Genetic and cellular analyses showed that HB53 regulates plant architecture by controlling the elongation and division of ligular adaxial and abaxial cells. Taken together, these findings uncover the phyB-LG1-HB53 regulatory module as a key molecular mechanism governing plant architecture and density tolerance, providing potential genetic targets for breeding maize hybrid varieties suitable for high-density planting.
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Fitocromo B , Proteínas de Plantas , Zea mays , Zea mays/crecimiento & desarrollo , Zea mays/genética , Zea mays/metabolismo , Zea mays/efectos de la radiación , Fitocromo B/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/efectos de la radiación , LuzRESUMEN
Leaf angle (LA) is a crucial factor that affects planting density and yield in maize. However, the regulatory mechanisms underlying LA formation remain largely unknown. In this study, we performed a comparative histological analysis of the ligular region across various maize inbred lines and revealed that LA is significantly influenced by a two-step regulatory process involving initial cell elongation followed by subsequent lignification in the ligular adaxial sclerenchyma cells (SCs). Subsequently, we performed both bulk and single-nucleus RNA sequencing, generated a comprehensive transcriptomic atlas of the ligular region, and identified numerous genes enriched in the hypodermal cells that may influence their specialization into SCs. Furthermore, we functionally characterized two genes encoding atypical basic-helix-loop-helix (bHLH) transcription factors, bHLH30 and its homolog bHLH155, which are highly expressed in the elongated adaxial cells. Genetic analyses revealed that bHLH30 and bHLH155 positively regulate LA expansion, and molecular experiments demonstrated their ability to activate the transcription of genes involved in cell elongation and lignification of SCs. These findings highlight the specialized functions of ligular adaxial SCs in LA regulation by restricting further extension of ligular cells and enhancing mechanical strength. The transcriptomic atlas of the ligular region at single-nucleus resolution not only deepens our understanding of LA regulation but also enables identification of numerous potential targets for optimizing plant architecture in modern maize breeding.
Asunto(s)
Regulación de la Expresión Génica de las Plantas , Hojas de la Planta , Proteínas de Plantas , Zea mays , Zea mays/genética , Zea mays/crecimiento & desarrollo , Zea mays/metabolismo , Zea mays/citología , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Perfilación de la Expresión Génica , Transcriptoma/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Núcleo Celular/metabolismo , Núcleo Celular/genéticaRESUMEN
Starch is a major storage carbohydrate in plants and is critical in crop yield and quality. Starch synthesis is intricately regulated by internal metabolic processes and external environmental cues; however, the precise molecular mechanisms governing this process remain largely unknown. In this study, we revealed that high red to far-red (high R:FR) light significantly induces the synthesis of leaf starch and the expression of synthesis-related genes, whereas low R:FR light suppress these processes. Arabidopsis phytochrome B (phyB), the primary R and FR photoreceptor, was identified as a critical positive regulator in this process. Downstream of phyB, basic leucine zipper transcription factor ELONGATED HYPOCOTYL5 (HY5) was found to enhance starch synthesis, whereas the basic helix-loop-helix transcription factors PHYTOCHROME INTERACTING FACTORs (PIF3, PIF4, and PIF5) inhibit starch synthesis in Arabidopsis leaves. Notably, HY5 and PIFs directly compete for binding to a shared G-box cis-element in the promoter region of genes encoding starch synthases GBSS, SS3, and SS4, which leads to antagonistic regulation of their expression and, consequently, starch synthesis. Our findings highlight the vital role of phyB in enhancing starch synthesis by stabilizing HY5 and facilitating PIFs degradation under high R:FR light conditions. Conversely, under low R:FR light, PIFs predominantly inhibit starch synthesis. This study provides insight into the physiological and molecular functions of phyB and its downstream transcription factors HY5 and PIFs in starch synthesis regulation, shedding light on the regulatory mechanism by which plants synchronize dynamic light signals with metabolic cues to module starch synthesis.
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Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Fitocromo B , Almidón , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Luz , Fototransducción , Fitocromo B/metabolismo , Fitocromo B/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/efectos de la radiación , Almidón/metabolismo , Almidón/biosíntesisRESUMEN
Identification and functional analysis of key genes regulated by the circadian clock system will provide a comprehensive understanding of the underlying mechanisms through which circadian clock disruption impairs the health of living organisms. The initial phase involved bioinformatics analysis, drawing insights from three RNA-seq datasets (GSE184303, GSE114400, and GSE199061) derived from wild-type mouse liver tissues, which encompassed six distinct time points across a day. As expected, 536 overlapping genes exhibiting rhythmic expression patterns were identified. By intersecting these genes with differentially expressed genes (DEGs) originating from liver RNA-seq data at two representative time points (circadian time, CT: CT2 and CT14) in global Bmal1 knockout mice (Bmal1-/-), hepatocyte-specific Bmal1 knockout mice (L-Bmal1-/-), and their corresponding control groups, 80 genes potentially regulated by BMAL1 (referred to as BMAL1-regulated genes, BRGs) were identified. These genes were significantly enriched in glycolipid metabolism, immune response, and tumorigenesis pathways. Eight BRGs (Nr1d1, Cry1, Gys2, Homer2, Serpina6, Slc2a2, Nmrk1, and Upp2) were selected to validate their expression patterns in both control and L-Bmal1-/- mice livers over 24 h. Real-time quantitative polymerase chain reaction results demonstrated a comprehensive loss of rhythmic expression patterns in the eight selected BRGs in L-Bmal1-/- mice, in contrast to the discernible rhythmic patterns observed in the livers of control mice. Additionally, significant reductions in the expression levels of these selected BRGs, excluding Cry1, were also observed in L-Bmal1-/- mice livers. Chromatin immunoprecipitation (ChIP)-seq (GSE13505 and GSE39860) and JASPAR analyses validated the rhythmic binding of BMAL1 to the promoter and intron regions of these genes. Moreover, the progression of conditions, from basic steatosis to non-alcoholic fatty liver disease, and eventual malignancy, demonstrated a continuous gradual decline in Bmal1 transcripts in the human liver. Combining the aforementioned BRGs with DEGs derived from human liver cancer datasets identified Gys2 and Upp2 as potential node genes bridging the circadian clock system and hepatocellular carcinoma (HCC). In addition, CCK8 and wound healing assays demonstrated that the overexpression of human GYS2 and UPP2 proteins inhibited the proliferation and migration of HepG2 cells, accompanied by elevated expression of p53, a tumor suppressor protein. In summary, this study systematically identified rhythmic genes in the mouse liver, and a subset of circadian genes potentially regulated by BMAL1. Two circadian genes, Gys2 and Upp2, have been proposed and validated as potential candidates for advancing the prevention and treatment of HCC.
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Carcinoma Hepatocelular , Relojes Circadianos , Neoplasias Hepáticas , Animales , Humanos , Ratones , Factores de Transcripción ARNTL/genética , Factores de Transcripción ARNTL/metabolismo , Carcinoma Hepatocelular/patología , Relojes Circadianos/genética , Ritmo Circadiano/genética , Proteínas CLOCK/genética , Regulación de la Expresión Génica , Proteínas de Andamiaje Homer/metabolismo , Hígado/metabolismo , Neoplasias Hepáticas/patología , Ratones Noqueados , Uridina Fosforilasa/metabolismo , Glucógeno Sintasa/metabolismoRESUMEN
The mammalian circadian clock is an endogenously regulated oscillator that is synchronized with solar time and cycle within a 24-h period. The circadian clock exists not only in the suprachiasmatic nucleus (SCN) of the hypothalamus, a central pacemaker of the circadian clock system, but also in numerous peripheral tissues known as peripheral circadian oscillators. The SCN and peripheral circadian oscillators mutually orchestrate the diurnal rhythms of various physiological and behavioral processes in a hierarchical manner. In the past two decades, peripheral circadian oscillators have been identified and their function has been determined in the mammalian reproductive system and its related endocrine glands, including the hypothalamus, pituitary gland, ovaries, testes, uterus, mammary glands, and prostate gland. Increasing evidence indicates that both the SCN and peripheral circadian oscillators play discrete roles in coordinating reproductive processes and optimizing fertility in mammals. The present study reviews recent evidence on circadian clock regulation of reproductive function in the hypothalamic-pituitary-gonadal axis and reproductive system. Additionally, we elucidate the effects of chronodisruption (as a result of, for example, shift work, jet lag, disrupted eating patterns, and sleep disorders) on mammalian reproductive performance from multiple aspects. Finally, we propose potential behavioral changes or pharmaceutical strategies for the prevention and treatment of reproductive disorders from the perspective of chronomedicine. Conclusively, this review will outline recent evidence on circadian clock regulation of reproduction, providing novel perspectives on the role of the circadian clock in maintaining normal reproductive functions and in diseases that negatively affect fertility.
Asunto(s)
Relojes Circadianos , Animales , Masculino , Femenino , Reproducción , Eje Hipotálamico-Pituitario-Gonadal , MamíferosRESUMEN
Trophoblast plays a crucial role in gestation maintenance and embryo implantation, partly due to the synthesis of progesterone. It has been demonstrated that hypoxia regulates invasion, proliferation, and differentiation of trophoblast cells. Additionally, human trophoblasts display rhythmic expression of circadian clock genes. However, it remains unclear if the circadian clock system is present in goat trophoblast cells (GTCs), and its involvement in hypoxia regulation of steroid hormone synthesis remains elusive. In this study, immunofluorescence staining revealed that both BMAL1 and NR1D1 (two circadian clock components) were highly expressed in GTCs. Quantitative real-time PCR analysis showed that several circadian clock genes were rhythmically expressed in forskolin-synchronized GTCs. To mimic hypoxia, GTCs were treated with hypoxia-inducing reagents (CoCl2 or DMOG). Quantitative real-time PCR results demonstrated that hypoxia perturbed the mRNA expression of circadian clock genes and StAR. Notably, the increased expression of NR1D1 and the reduction of StAR expression in hypoxic GTCs were also detected by western blotting. In addition, progesterone secretion exhibited a notable decline in hypoxic GTCs. SR9009, an NR1D1 agonist, significantly decreased StAR expression at both the mRNA and protein levels and markedly inhibited progesterone secretion in GTCs. Moreover, SR8278, an NR1D1 antagonist, partially reversed the inhibitory effect of CoCl2 on mRNA and protein expression levels of StAR and progesterone synthesis in GTCs. Our results demonstrate that hypoxia reduces StAR expression via the activation of NR1D1 signaling in GTCs, thus inhibiting progesterone synthesis. These findings provide new insights into the NR1D1 regulation of progesterone synthesis in GTCs under hypoxic conditions.
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Progesterona , Trofoblastos , Animales , Humanos , Trofoblastos/metabolismo , Cabras/genética , Hipoxia , ARN Mensajero , Cobalto , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/metabolismoRESUMEN
Senescence is the final stage of leaf development, limits and dictates the longevity of leaf. This stage is strictly controlled by internal developmental age signals and external environmental signals. However, the underlying mechanisms by which various signals integrating together to regulate leaf senescence remain largely unknown. Here, we show that the light signalling protein FAR-RED ELONGATED HYPOCOTYL3 (FHY3) directly represses the transcription of PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and NON-YELLOWING1/STAY-GREEN1 (NYE1/SGR1), two key regulators of senescence, thus preventing chlorophyll degradation and extending the leaf longevity in Arabidopsis thaliana. Disrupting either PIF4 or NYE1 function completely rescued the early leaf senescence of fhy3-4 mutant. Interestingly, we found that FHY3 competes with PIF4 to bind to the G-box cis-element in NYE1 promoter, subsequently preventing the transcriptional activation of this gene by PIF4. Moreover, FHY3 transcript levels gradually increased in senescent leaves, which consist with disrupting FHY3 function accelerated chlorophyll degradation and shorted the leaf longevity. All these findings reveal that FHY3 is a master regulator that participates in multiple signalling pathways to increase leaf longevity. In addition, our study shed light on the dynamic regulatory mechanisms by which plants integrate light signalling and internal developmental cues to control leaf senescence and longevity.
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Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Hojas de la Planta/metabolismo , Activación Transcripcional , Clorofila/metabolismo , Regulación de la Expresión Génica de las Plantas , Fitocromo/metabolismoRESUMEN
The circadian clock and autophagy are essential biological mechanisms involved in regulating many physiological processes. Accumulating evidence has revealed that autophagic activity is regulated by the circadian clock system. However, whether autophagy regulates the circadian clock system remains unclear. In this study, rapamycin and AICAR, two classical activators of autophagy, were used to create autophagy activation models in BMAL1-dLuc U2OS cell line. The results showed that the mRNA expression of MAP1LC3B and ATG5 were significantly upregulated after autophagy activation, whereas the mRNA expression of circadian clock genes (BMAL1, PER2, REV-ERBα, and DBP) were significantly decreased. Consistent with these data, the relative ratio of LC3-II/LC3-I and the protein level of ATG5 were increased after rapamycin or AICAR treatment. In contrast, BMAL1 and REV-ERBα levels were decreased. Notably, the mRNA expression of circadian clock genes (BMAL1, PER2, REV-ERBα, and DBP) and autophagy-related genes (MAP1LC3B and ATG5) showed rhythmic expression patterns in both untreated and rapamycin/AICAR-treated U2OS cells. Moreover, the autophagy inhibitor 3-methyladenine partially reversed the inhibitory effects of autophagy on circadian clock genes expression and BMAL1-Luc oscillations. Another critical finding was that ATG5 knockout alleviates the inhibitory effect of rapamycin-mediated autophagy activation on the circadian clock oscillators in U2OS cells. Collectively, our data indicate that autophagy activation attenuates the circadian clock oscillators in U2OS cells via the ATG5 pathway.
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Relojes Circadianos , Relojes Circadianos/genética , Factores de Transcripción ARNTL/genética , Factores de Transcripción ARNTL/metabolismo , Ritmo Circadiano/fisiología , ARN Mensajero/metabolismo , Autofagia , Sirolimus/farmacologíaRESUMEN
The mammalian internal circadian clock system has been evolved to adapt to the diurnal changes in the internal and external environment of the organism to regulate diverse physiological functions, such as the sleep-wake cycle and feeding rhythm, thereby coordinating the rhythmic changes of energy demand and nutrition supply in each diurnal cycle. The circadian clock regulates glucose metabolism, lipid metabolism, and hormones secretion in diverse tissues and organs, including the liver, skeletal muscle, pancreas, heart, and vessels. As a special "organ" of the host, the gut microbiota, together with the intestinal microenvironment (tissues, cells, and metabolites) in a co-evolutionary process, constitutes a micro-ecosystem and plays an important role in the process of nutrient digestion and absorption in the intestine of the host. In recent years, accumulating evidence indicates that the compositions, quantities, colonization, and functional activities of the gut microbiota exhibit significant circadian variations, which are closely related to the changes of various physiological functions under the regulation of host circadian clock system. In addition, several studies have shown that the gut microbiota can produce many important metabolites such as the short-chain fatty acids through the degradation of indigestive dietary fibers. A portion of gut microbiota-derived metabolites can regulate the circadian clock system and metabolism of the host. This article mainly discusses the interaction between the host circadian clock system and the gut microbiota, and highlights its influence on energy metabolism of the host, providing a novel clues and thought for the prevention and treatment of metabolic diseases.
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Relojes Circadianos , Microbioma Gastrointestinal , Animales , Relojes Circadianos/fisiología , Ritmo Circadiano/fisiología , Ecosistema , Metabolismo Energético , Microbioma Gastrointestinal/fisiología , Metabolismo de los Lípidos/fisiología , MamíferosRESUMEN
Senile animals exhibit a high risk of elevated endoplasmic reticulum (ER) stress, attenuated circadian clock, and impaired steroidogenesis in testes. However, how these three processes are intertwined in mouse Leydig cells remains unclear. In this study, a mouse model of aging and hydrogen peroxide (H2O2)-induced senescent TM3 Leydig cells were used to dissect the connections among ER stress, circadian oscillators, and steroidogenesis in Leydig cells. Additionally, thapsigargin (Tg, 60 nM)/tunicamycin (Tm, 60 ng/mL)-induced ER stress were established to investigate the underlying mechanisms by which ER stress regulated testosterone synthesis via circadian clock-related signaling pathways in TM3 cells and primary Leydig cells. Elevated ER stress, attenuated circadian clock, and diminished steroidogenesis were detected in the testes of aged mice (24-month-old) and H2O2-induced (200 µM) senescent TM3 cells in comparison with their control groups. Tg/Tm-induced ER stress reduced the transcription of the circadian clock and steroidogenic genes in TM3 cells and LH-treated (100 ng/mL) primary Leydig cells. Furthermore, 4-phenylbutyric acid (4-PBA, 1 µM), an inhibitor of ER stress, alleviated the inhibitory effect of Tg-mediated ER stress on Per2:Luc oscillations in primary Leydig cells isolated from mPer2Luc knock-in mice, and attenuated the repressive effect of H2O2-induced or Tg-mediated ER stress on the transcription of circadian clock and steroidogenic genes expression and testosterone synthesis in TM3 cells. Collectively, these data indicate that age-related ER stress represses testosterone synthesis via attenuation of the circadian clock in Leydig cells.
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Relojes Circadianos , Células Intersticiales del Testículo , Animales , Relojes Circadianos/genética , Estrés del Retículo Endoplásmico , Peróxido de Hidrógeno/metabolismo , Células Intersticiales del Testículo/metabolismo , Masculino , Ratones , Testosterona/metabolismoRESUMEN
The circadian clock system is based on interlocked positive and negative transcriptional and translational feedback loops of core clock genes and their encoded proteins. The mammalian circadian clock system has been extensively investigated using mouse models, but has been poorly investigated in diurnal ruminants. In this study, goat embryonic fibroblasts (GEFs) were isolated and used as a cell model to elucidate the caprine circadian clock system. Real-time quantitative PCR analysis showed that several clock genes and clock-controlled genes were rhythmically expressed in GEFs over a 24 h period after dexamethasone stimulation. Immunofluorescence revealed that gBMAL1 and gNR1D1 proteins were expressed in GEFs, and western blotting analysis further verified that the proteins were expressed with circadian rhythmic changes. Diurnal changes in clock and clock-controlled gene expression at the mRNA and protein levels were also observed in goat liver and kidney tissues at two representative time points in vivo. Amino acid sequences and tertiary structures of goat BMAL1 and CLOCK proteins were found to be highly homologous to those in mice and humans. In addition, a set of goat representative clock gene orthologs and the promoter regions of two clock genes of goats and mice were cloned. Dual-luciferase reporter assays showed that gRORα could activate the promoter activity of the goat BMAL1, while gNR1D1 repressed it. The elevated pGL4.10-gNR1D1-Promoter-driven luciferase activity induced by mBMAL1/mCLOCK was much higher than that induced by gBMAL1/gCLOCK, and the addition of gCRY2 or mPER2 repressed it. Real-time bioluminescence assays revealed that the transcriptional activity of BMAL1 and NR1D1 in goats and mice exhibited rhythmic changes over a period of approximately 24 h in NIH3T3 cells or GEFs. Notably, the amplitudes of gBMAL1 and gNR1D1 promoter-driven luciferase oscillations in NIH3T3 cells were higher than those in GEFs, while mBMAL1 and mNR1D1 promoter-driven luciferase oscillations in NIH3T3 cells had the highest amplitude. In sum, transcriptional and translational loops of the mammalian circadian clock system were found to be broadly conserved in goats and not as robust as those found in mice, at least in the current experimental models. Further studies are warranted to elucidate the specific molecular mechanisms involved.
RESUMEN
Autophagy of granulosa cells (GCs) is involved in follicular atresia, which occurs repeatedly during the ovarian development cycle. Several circadian clock genes are rhythmically expressed in both rodent ovarian tissues and GCs. Nuclear receptor subfamily 1 group D member 1 (NR1D1), an important component of the circadian clock system, is involved in the autophagy process through the regulation of autophagy-related genes. However, there are no reports illustrating the role of the circadian clock system in mouse GC autophagy. In the present study, we found that core circadian clock genes (Bmal1, Per2, Nr1d1, and Dbp) and an autophagy-related gene (Atg5) exhibited rhythmic expression patterns across 24 h in mouse ovaries and primary GCs. Treatment with SR9009, an agonist of NR1D1, significantly reduced the expression of Bmal1, Per2, and Dbp in mouse GCs. ATG5 expression was significantly attenuated by SR9009 treatment in mouse GCs. Conversely, Nr1d1 knockdown increased ATG5 expression in mouse GCs. Decreased NR1D1 expression at both the mRNA and protein levels was detected in the ovaries of Bmal1-/- mice, along with elevated expression of ATG5. Dual-luciferase reporter assay and electrophoretic mobility shift assay showed that NR1D1 inhibited Atg5 transcription by binding to two putative retinoic acid-related orphan receptor response elements within the promoter. In addition, rapamycin-induced autophagy and ATG5 expression were partially reversed by SR9009 treatment in mouse GCs. Taken together, our current data demonstrated that the circadian clock regulates GC autophagy through NR1D1-mediated inhibition of ATG5 expression, and thus, plays a role in maintaining autophagy homeostasis in GCs.
Asunto(s)
Proteína 5 Relacionada con la Autofagia/biosíntesis , Autofagia/fisiología , Relojes Circadianos/fisiología , Ritmo Circadiano/fisiología , Células de la Granulosa/metabolismo , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/biosíntesis , Animales , Proteína 5 Relacionada con la Autofagia/antagonistas & inhibidores , Proteína 5 Relacionada con la Autofagia/genética , Células Cultivadas , Péptidos y Proteínas de Señalización del Ritmo Circadiano/biosíntesis , Péptidos y Proteínas de Señalización del Ritmo Circadiano/genética , Femenino , Células de la Granulosa/patología , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares/genéticaRESUMEN
The circadian clock system plays an important role in regulating testosterone synthesis in mammals. Male Bmal1-/- mice are infertile with low serum testosterone levels and decreased expression of testicular steroidogenic genes, suggesting that circadian clock genes regulate testosterone biosynthesis by activating steroidogenic gene transcription. However, whether the circadian clock regulates testosterone production via other genes remains unknown. Using Bmal1-/- mice and their wild-type (WT) siblings, we aimed to identify additional genes by which the circadian clock regulates testosterone synthesis. WT and Bmal1-/- mouse testes sections had similar normal morphologies, although there was a decrease in testicular spermatozoa in the Bmal1-/- mice. Low serum testosterone levels were detected in the Bmal1-/- mice. RNA sequencing identified 37 and 48 genes that were differentially expressed between WT and Bmal1-/- mouse testes at circadian time (CT2 and CT14), respectively. The cholesterol metabolism pathway was significantly enriched in the KEGG pathway analysis, and there was lower expression of three apolipoprotein genes (Apoa1, Apoa2, and Apoc3) at CT2 in the testes of Bmal1-/- mice than in those of WT mice. These decreases in Apoa1, Apoa2, and Apoc3 expression were verified by quantitative polymerase chain reaction analysis, which also revealed downregulation of the expression of the circadian clock (Per2, Dbp, and Nr1d1) and steroidogenic (StAR, Cyp11a1, and Hsd17b3) genes. The expression of circadian clock genes was relatively stable in WT mice over a 20-h period, whereas there was clear circadian rhythmic expression of Apoa1, Apoa2, Apoc3, StAR, Cyp11a1, Hsd3b2, and Hsd17b3. Bmal1-/- mice showed severely reduced expression of testicular circadian clock genes at three time points (CT4, CT12, and CT20), and a reduction in mRNA expression levels of Apo (Apoa1, Apoa2, and Apoc3) and steroidogenic (StAR, Cyp11a1, Hsd3b2, and Hsd17b3) genes. Oil Red O staining showed decreased lipid aggregation in the Leydig cells of Bmal1-/- mouse testes. Considering the vital role of Apo genes in high-density lipoprotein formation and cholesterol transport, the present data suggest that the circadian clock system regulates testosterone production by orchestrating the rhythmic expression of Apo genes. These data extend our understanding of the role of the circadian clock in regulating testosterone production in mammals.
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Relojes Circadianos , Testosterona , Animales , Apolipoproteínas , Proteínas CLOCK/genética , Ritmo Circadiano , Expresión Génica , Regulación de la Expresión Génica , Masculino , Ratones , TestículoRESUMEN
Glyphosate is a broad-spectrum herbicide that impairs testosterone synthesis in mammals. Leydig cells (LCs), the primary producers of testosterone, demonstrate rhythmic expression of circadian clock genes both in vivo and in vitro. The nuclear receptor NR1D1 is an important clock component that constitutes the subsidiary transcriptional/translational loop in the circadian clock system. Nr1d1 deficiency resulted in diminished fertility in both male and female mice. However, whether NR1D1 is involved in the glyphosate-mediated inhibition of testosterone synthesis in LCs remains unclear. Here, the involvement of NR1D1 in glyphosate-mediated inhibition of testosterone synthesis was investigated both in vitro and in vivo. Glyphosate exposure of TM3 cells significantly increased Nr1d1 mRNA levels, but decreased Bmal1, Per2, StAR, Cyp11a1, and Cyp17a1 mRNA levels. Western blotting confirmed elevated NR1D1 and reduced StAR protein levels following glyphosate exposure. Glyphosate exposure also reduced testosterone production in TM3 cells. In primary LCs, glyphosate exposure also upregulated Nr1d1 mRNA levels and downregulated the mRNA levels of other clock genes (Bmal1 and Per2) and steroidogenic genes (StAR, Cyp17a1, Cyp11a1, and Hsd3b2), and inhibited testosterone synthesis. Moreover, glyphosate exposure significantly reduced the amplitude and shortened the period of PER2::LUCIFERASE oscillations in primary LCs isolated from mPer2Luciferase knock-in mice. Four weeks of oral glyphosate upregulated NR1D1 at both the mRNA and protein levels in mouse testes, and this was accompanied by a reduction in StAR expression. Notably, serum testosterone levels were also drastically reduced in mice treated with glyphosate. Moreover, dual-luciferase reporter and EMSA assays revealed that in TM3 cells NR1D1 inhibits the expression of StAR by binding to a canonical RORE element present within its promoter. Together, these data demonstrate that glyphosate perturbs testosterone synthesis via NR1D1 mediated inhibition of StAR expression in mouse LCs. These findings extend our understanding of how glyphosate impairs male fertility.
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Relojes Circadianos , Células Intersticiales del Testículo , Animales , Femenino , Glicina/análogos & derivados , Glicina/toxicidad , Masculino , Ratones , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares , Testosterona , GlifosatoRESUMEN
The circadian clock is an endogenous timekeeper system that generates biological rhythms of approximately 24 h in most organisms. EARLY FLOWERING 3 (ELF3) and ELF4 were initially identified as negative regulators of flowering time in Arabidopsis thaliana. They were then found to play crucial roles in the circadian clock by integrating environmental light and ambient temperature signals and transmitting them to the central oscillator, thereby regulating various downstream cellular and physiological processes. At dusk, ELF3 acts as a scaffold, interacting with ELF4 and the transcription factor LUX ARRHYTHMO (PHYTOCLOCK1) to form an EVENING COMPLEX (EC). This complex represses the transcription of multiple circadian clock-related genes, thus inhibiting hypocotyl elongation and flowering. Subsequent studies have expanded knowledge about the regulatory roles of the EC in thermomorphogenesis and shade responses. In addition, ELF3 and ELF4 also form multiple complexes with other proteins including chromatin remodeling factors, histone deacetylase, and transcription factors, thus enabling the transcriptional repression of diverse targets. In this review, we summarize the recent advances in elucidating the regulatory mechanisms of ELF3 and ELF4 in plants and discuss directions for future research on ELF3 and ELF4.
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Proteínas de Arabidopsis/fisiología , Arabidopsis/metabolismo , Factores de Transcripción/fisiología , Proteínas de Arabidopsis/metabolismo , Ritmo Circadiano , Regulación de la Expresión Génica de las Plantas , Factores de Transcripción/metabolismoRESUMEN
OBJECTIVE: To compare influence of retention or resection subpatellar fat pad on patella height during rheumatoid knee replacement. METHODS: Totally 48 patients with rheumatoid arthritis who underwent total knee replacement from October 2013 to October 2017 were retrospectively analyzed and divided into resection and retention subpatellar fat pad group. There were 23 patients in resection subpatellar fat pad group, including 9 males and 14 females aged from 48 to 69 years old with an average of(55.83±5.65) years old; subpatellar fat pad were resected during opertaion. There were 25 patients in retention subpatellar fat pad group, including 6 males and 19 femlaes aged from 49 to 70 years old with an average age of (55.52± 6.28) years old;subpatellar fat pad were retentedduring opertaion. Postopertaive complications were observed between two groups, visual analogue scale (VAS) and Hospital for Special Surgery (HSS) at 1 year after operation were used to evaluate relieve pain degree and clnical effect of knee joint, Insall-Salvati ratio(I-S ratio) was used to compare changes of postoperative patella height at 1 year after operation. RESULTS: All patients were followed up from 12 to 39 months with an average of (23.85± 8.82) months. The postoperative wound healed well without infection complications and no prosthetic loosening or revision. Postoperative VAS score at 1 year between two groups was lower than that of before opertaion(P<0.05), but no statistical difference between two groups at 1 year after operation(P>0.05). Postopertaive HSS score between two groups was higer than that of before operation(P<0.05), while no difference in HSS score at 1 year after operation between two groups (P>0.05). I-S ratio of subpatellar fat pad resection group (1.03±0.04) was lower than that of subpatellar fat pad retention group (1.06±0.06), and difference was statistically significant (P<0.05). CONCLUSION: Resection or retention subpatellar fat pad in rheumatoid knee replacement have advantages of relieving postoperative pain and improving functional recovery, however, retention of infrapatellar fat pad is beneficial to restoration of patellar height.
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Artroplastia de Reemplazo de Rodilla , Rótula , Tejido Adiposo , Anciano , Artroplastia de Reemplazo de Rodilla/efectos adversos , Femenino , Humanos , Articulación de la Rodilla/cirugía , Masculino , Persona de Mediana Edad , Rótula/cirugía , Estudios RetrospectivosRESUMEN
Light is one of the most important environmental factors affecting plant growth and development. Plants use shade avoidance or tolerance strategies to adjust their growth and development thus increase their success in the competition for incoming light. To investigate the mechanism of shade responses in maize (Zea mays), we examined the anatomical and transcriptional dynamics of the early shade response in seedlings of the B73 inbred line. Transcriptome analysis identified 912 differentially expressed genes, including genes involved in light signaling, auxin responses, and cell elongation pathways. Grouping transcription factor family genes and performing enrichment analysis identified multiple types of transcription factors that are differentially regulated by shade and predicted putative core genes responsible for regulating shade avoidance syndrome. For functional analyses, we ectopically over-expressed ZmHB53, a type II HD-ZIP transcription factor gene significantly induced by shade, in Arabidopsis thaliana. Transgenic Arabidopsis plants overexpressing ZmHB53 exhibited narrower leaves, earlier flowering, and enhanced expression of shade-responsive genes, suggesting that ZmHB53 might participates in the regulation of shade responses in maize. This study increases our understanding of the regulatory network of the shade response in maize and provides a useful resource for maize genetics and breeding.
Asunto(s)
Fototransducción , Transcriptoma , Zea mays/fisiología , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Luz , Proteínas de Plantas/genética , Plantones/genética , Plantones/fisiología , Factores de Transcripción/genética , Zea mays/genéticaRESUMEN
Sugars provide a source of energy; they also function as signaling molecules that regulate gene expression, affect metabolism, and alter growth in plants. Rapid responses to sugar signaling and metabolism are essential for optimal growth and fitness, but the regulatory mechanisms underlying these are largely unknown. In this study, we found that the rapid induction of sugar responses in Arabidopsis (Arabidopsis thaliana) requires the W-box cis-elements in the promoter region of GLC 6-PHOSPHATE/PHOSPHATE TRANSLOCATOR2, a well-studied sugar response marker gene. The transcription factors WRKY18 and WRKY53 directly bind to the W-Box cis-elements in the promoter region of sugar response genes and activate their expression. In addition, HISTONE ACETYLTRANSFERASE 1 (HAC1) is recruited to the WRKY18 and WRKY53 complex that resides on the promoters. In this complex, HAC1 facilitates the acetylation of histone 3 Lys 27 (H3K27ac) on the sugar-responsive genes. Taken together, our findings demonstrate a mechanism by which sugar regulates chromatin modification and gene expression, thus helping plants to adjust their growth in response to environmental changes.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efectos de los fármacos , Arabidopsis/metabolismo , Proteínas de Unión al ADN/metabolismo , Histona Acetiltransferasas/metabolismo , Azúcares/farmacología , Factores de Transcripción/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/genética , Histona Acetiltransferasas/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Factores de Transcripción/genéticaRESUMEN
BACKGROUND: Interleukin-17 (IL-17), a pleiotropic cytokine, plays a significant role in the inflammatory diseases. By a pilot study with small population, IL-17 polymorphisms (IL-17A rs2275913 and IL-17F rs763780) showed a more potential risk factor in knee osteoarthritis (OA) in our recruited subjects. In the current study, the association between IL-17A rs2275913 and IL-17F rs763780and the risk of OA in a Chinese population is studied. METHODS: The IL-17A rs2275913 and IL-17F rs763780 polymorphisms were determined in 594 knee OA cases and 576 healthy controls, using polymerase chain reaction-restriction fragment length polymorphism assay. The relationship between genotype distribution and disease risk, as well as OA severity was analyzed by Chi-square test and multivariate logistic regression. RESULTS: The experimental results indicated that the polymorphism in IL-17 gene rs2275913 site were related to knee OA risk after the adjustment of BMI, sex, age, smoking and drinking status (AA vs. GG: odds ratio (OR), 1.411; 95% confidence interval (CI), 1.021-1.950; P = 0.040; A allele vs. G allele: OR, 1.192; P = 0.037; 95% CI, 1.012-1.404;). Similarly, subjects who are bearing the rs763780 variant genotypes (TC and CC) and C allele also had a higher susceptibility to knee OA compared with those who are bearing the TT genotype (TC vs. TT, OR: 1.312; P = 0.039; 95% CI: 1.017-1.692; CC vs. TT, OR: 2.812, P = 0.006, 95% CI: 1.338-5.909; C allele Vs. T allele, OR:1.413, P = 0.002, 95% CI:1.141-1.751). In the meantime, one high-risk haplotypes, AC (OR was 7.22, P < 0.01) was found. Both two polymorphisms do not correlated with OA severity based on Kellgren-Lawrence (K&L) scales. Finally, serum IL-17 levels of knee OA patients were greatly higher than those of controls (P = 0.001). CONCLUSIONS: With the limited size sample, our study shows that IL-17 gene polymorphisms possibly related to the high-risk knee OA occurrence.